# New heat pump



## roughneck (Nov 28, 2014)

Should come up a bit quicker then that. What are you using for auxiliary heat?
What does the commissioning report say about heat rise across the air handler? Or supply air temperature?


----------



## dohat2 (Jan 29, 2021)

Unfortunately this is an emergency job I'm not any contractors in NYC provide that kind of report. No emergency or backup heat

It cost 15k total, I'm curious do you know how much emergency heat add-on would cost

Also I'm assuming that once desired temperature is reached then it will be able to maintain that even if outdoor temperatures fall to 20 again


----------



## Missouri Bound (Apr 9, 2011)

You contractor needs to check the charge.
And no heat pump in that climate should be installed without aux. heat.....period.


----------



## roughneck (Nov 28, 2014)

What is the model number of the heat pump and air handler?


----------



## user_12345a (Nov 23, 2014)

That heatpump should maintain heating capacity as it gets colder much better than a regular heatpump.

Granted, it has to be matched to the right coil and have proper airflow to run at full capacity, it modulates to maintain specific coil temperature.

Should have aux heat, but shouldn't need it much.


----------



## dohat2 (Jan 29, 2021)

AIr Handler Unit Model - BVA-36WN1-M20 Model Number 8733952440 (3 ton)
Condensing Unit Model BOVA-36HDN1-M20G Model Number 8733952437 (3 ton)

The heat pump is installed in the basement and serves basement & 1st floor (total 1500 sq feet), There is a return air duct to the 1st floor but some return comes from the basement too. In the attic, I have an older gas-furnace combo heating/cooling unit that I also plan to replace and that's serving the 2nd floor which is about 800 sq feet

Thanks


----------



## dohat2 (Jan 29, 2021)

Also I have a I have a honeywell 9320. Not sure if heat pumps need a better thermostat but I did read that this thermostat supports heat pumps


----------



## beenthere (Oct 11, 2008)

At 20°F outdoor temp, when the indoor temp is 70, and the air handler is moving 1150 CFM, your only going to get 28,000 BTUs of heat. And when its 10°F outside, your only going to get 25,000 BTUs. May not hold temp real well at your lower outdoor temps.


----------



## Half-fast eddie (Sep 19, 2020)

Is it possible to properly install a system in cold weather? I thought the ambient temp needed to be relatively high to be able to properly charge the freon. 

And for cost ... sounds like he got screwed. This summer we installed a new carrier heat pump system. New evap and condenser, new line sets, new t-stat and it was $5k.


----------



## dohat2 (Jan 29, 2021)

4aam EST update - I measured the supply duct air with an accurate kitchen thermometer and all ducts are between 84-88. Temp is up to 56 now and outdoor temp is 18

As a side note, I did see some dirt in the ductwork which I'll clean up with a vacuum in the morning. But if there is dirt here, it's possibly lower down and maybe I should get a duct cleaning company? See attached


----------



## roughneck (Nov 28, 2014)

That air handler has 5, 8, 10, 15, or 20 kw auxiliary heat kits available. You need auxiliary heat. 
Emergency job or not the equipment needs commissioned. It’s not going to function by turning the power on and walking away. 
What is that picture of?
Take a picture of the install of the indoor and outdoor units.


----------



## dohat2 (Jan 29, 2021)

A duct in the dining room


----------



## beenthere (Oct 11, 2008)

Half-fast eddie said:


> Is it possible to properly install a system in cold weather? I thought the ambient temp needed to be relatively high to be able to properly charge the freon.
> 
> And for cost ... sounds like he got screwed. This summer we installed a new carrier heat pump system. New evap and condenser, new line sets, new t-stat and it was $5k.


As long as you know the line set length on a new install, it is fairly easy.

Check on what it would cost you to buy the equipment he has, and you might find that your low price barely covers the wholesale cost of his equipment. Plus the OP lives in a high cost of living area. 

The contractor should have include electric aux heat, but he didn't.


----------



## sktn77a (May 11, 2009)

beenthere said:


> The contractor should have include electric aux heat, but he didn't.


OP: If the installer didn't include aux heat, call him back and tell him it need to be installed. Not expensive - the heating strips should be a couple hundred dollars and he should install it for free!


----------



## beenthere (Oct 11, 2008)

sktn77a said:


> OP: If the installer didn't include aux heat, call him back and tell him it need to be installed. Not expensive - the heating strips should be a couple hundred dollars and he should install it for free!


Why free? The OP never paid for aux heat to be included in the install.


----------



## Missouri Bound (Apr 9, 2011)

beenthere said:


> Why free? The OP never paid for aux heat to be included in the install.


But why didn't he? The climate in that area requires aux. heat.
That installer should have insisted that it be included.
If the circuit wasn't adequate that should have been explained when the heat pump was being sold so that it could have been addressed.
Now the customer paid $15,000 for a unit that won't keep him warm.
That is bullish*t.


----------



## beenthere (Oct 11, 2008)

The OP wasn't interested in aux heat.


----------



## Missouri Bound (Apr 9, 2011)

beenthere said:


> The OP wasn't interested in aux heat.


That doesn't matter.
Wherever sold him that unit had the responsibility to tell him he needed it in that climate even if it only gets energized during defrost cycles.
Now he's got a cold, upset customer.
I do understand that since he went from gas forced air to heat pump that he doesn't have the required ampacity for the resistance heat.
As I said in an earlier post that should have been addressed.
He should have stuck with a gas fired unit.

What pinheaded company would sell a unit that they knew wouldn't perform adequately in the climate it was installed?
Very shoddy.


----------



## HVACnut (Jan 25, 2021)

Dohat 2, you need aux heat for a heat pump to work up north. We live in SC and even need it here where temps at worse are in the low 30's. It will help get the temp up when you raise the thermostat, and you need it to keep the air warm when your unit goes into defrost (or it will blow cold air)

Are you sure it does not have it? What are the choices listed on your thermostat? Just AC and Heat? No Aux heat listed?


----------



## user_12345a (Nov 23, 2014)

Contractor shouldn't have offered to put in a hp without aux heat even though it's better than a conventional heatpump. Do it right or not at all.

There's a high probability in a a 1500 sq ft house, it's not getting full airflow and the model installed modulates down/up to maintain a certain coil temperature.

If the electrical service is only 100 amp, may be limited to adding like 5kw, which is an extra 17000 btu/hr - even that would make a big difference. 
To cover the entire heating load (in case of heatpump failure), probably need like 15kw +/- 5.


----------



## beenthere (Oct 11, 2008)

Missouri Bound said:


> That doesn't matter.
> Wherever sold him that unit had the responsibility to tell him he needed it in that climate even if it only gets energized during defrost cycles.
> Now he's got a cold, upset customer.
> I do understand that since he went from gas forced air to heat pump that he doesn't have the required ampacity for the resistance heat.
> ...


We don't know if the other company warned him or not. But he was only interested in getting a heat pump, and not getting aux heat.


----------



## roughneck (Nov 28, 2014)

OP, did the unit ever make it to setpoint? What updates do you have?


----------



## beenthere (Oct 11, 2008)

roughneck said:


> OP, did the unit ever make it to setpoint? What updates do you have?


At 1:30 PM today, his first floor was only at 57, and its been running since 11:AM yesterday. The area/first floor started out at 48°.


----------



## Old Thomas (Nov 28, 2019)

No emergency backup electric resistance heat? Even our central FL house has it but we never use it.


----------



## Missouri Bound (Apr 9, 2011)

HVACnut said:


> Are you sure it does not have it?


He said he went from gas fired to a heat pump.
A gas fired furnace can run on a single 20 amp circuit (indoors).
It's unlikely he had the circuitry.
But it should have been provided for the heat pump if aux heat was needed.
Or he should have stuck with gas fired.


----------



## HVACnut (Jan 25, 2021)

Any updates from the OP? Is your house still cold? You guys have a big snow storm on the way!


----------



## dohat2 (Jan 29, 2021)

Pics of install here (each pic has a text description) -


http://imgur.com/a/Utj5XmN

Video - 




Sorry guys - somehow this site didn't send me email notifications. AS of 5pm EST, it's 63 and in the morning, it went backwards from 63 to 62. But it's stayed at 63 all day long now with outdoor temps 22-24. Hence, since the time of installation, it's been 54 hours and has climbed from 48 to 63 (15 degrees). The contractor asked me about aux heat and I asked him if it's needed in our region and he said no it's not because the unit can perform up to 4 degrees

1) currently the unit has a ducted return to the 1st floor and also has a return in the basement too. The contractor is asking me to remove the side panel of the unit to get more airflow but I'm not sure if that's a good idea because I don't like return air from a boiler room as it's not the cleanest place and I still have a hot water heater there and being a 100 year old home, the fireplace soot still sometimes falls off into the exit and I clean it off but it's not sealed off yet even though we closed off the fireplace and have never used it
2) He had me measure the in/out temps or room temperature and supply temperature at unit itself. Room temp is 63, temp by basement return is 58 and at the unit, I inserted the thermometer at the canvas where unit connects to the whole supply ductwork and it's measuring 94. Does anybody know what bosch ids 2.0 claims the difference in intake/supply temp should be?
3) Also when I was doing this supply measurement at the unit, I suddenly felt cold air and it went on for about a minute. I ran out to check if the heat pump was running and it was not. I think within 1-2 mins it switched from cold to hot air. If this was the defrost cycle, does it really blow cold air into the supply? I also wonder if I should get a permanent thermometer and take historical readings which will identify how often it's going into defrost cycle
3) When I place a tissue on the 1st floor return, it doesn't stick and seems very little airflow over there (I do feel a little on the back of my hand). At the basement return, there is very strong return air and it's at least 5-7 times greater than the 1st floor return. A tissue held here 2 inches away will get sucked and stick to the vent

Thanks for all the advice here!


----------



## beenthere (Oct 11, 2008)

There are heat pumps that can "perform" down to -20°F. And they need aux heat to heat the house to set point.

The temp difference between intake and supply, varies with indoor temp, outdoor temp, and CFM the air handler is moving.

If your getting a 94° supply temp with a 58 degree return temp. Your not moving the amount of air you should be.


----------



## beenthere (Oct 11, 2008)

Your house temp will start to drop again tonight.


----------



## dohat2 (Jan 29, 2021)

What should be a good number instead of 94?

Do you think I should remove that side panel even though it will start gaining even more air directly from the boiler room which isn't the cleanest air


----------



## beenthere (Oct 11, 2008)

You should look and see what the blower speed/CFM is set for, and reset it to rough 1150 CFM,

Then check temp rise at the unit. 

Good chance you only moving around 800 CFM,


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> Pics of install here (each pic has a text description) -
> 
> 
> http://imgur.com/a/Utj5XmN
> ...


I'm sorry you got stuck with a nitwit contractor.
You need AUX heat to bring the temp of the residence to a point where it* can *keep up, as beenthere mentioned
And it certainly is needed when you go into defrost.
I'm curious about your air flow temperature.
What temp are you getting at a supply grill in your main area?
The return air on the main floor should be doing a lot more than it is.
Did you have the same air flow issue with the gas fired unit?


----------



## dohat2 (Jan 29, 2021)

supply grill tested in different rooms on the 1st floor are between 84-88. I remember that the air flow on the main floor was stronger with gas furnace and if I placed a kleenex tissue on it, it'll stick. Now it doesn't at all. From the unit it's about 24 feet to the 1st floor return - is that too long? It does go through about 6 feet through between beams where there is only sheet metal at the bottom (not the other 3 sides)

How do I change cfm from 800 to 1150 - is it a simple dip switch or something?

I'm ok if the recovery is going to take a few more days but I don't think it'll hold temperatures if it drops again to 10-15 outside. Aux heat can be the answer but in my scenario, I feel my system will use a LOT of aux heat below 32 degrees defeating the efficiency aspect of a heat pump altogether

Thx


----------



## roughneck (Nov 28, 2014)

As beenthere said, the system isn’t moving the correct amount of air. And you currently don’t have a 3 ton unit. With the outdoor temperature. 
With the airflow issues, the refrigerant charge could also be incorrect. And causing a drop in performance. 
The installation is generally sloppy. From the photos you posted.


----------



## beenthere (Oct 11, 2008)

95% of all heat pumps use aux heat.

Efficiency is one, being comfortable is another. 

Did they leave the install manual there, they should have. It will have instructions on how to set blower speed/CFM.


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> supply grill tested in different rooms on the 1st floor are between 84-88. I remember that the air flow on the main floor was stronger with gas furnace


Well you aren't too far off with the temperatures. 15-25 degrees is within a reasonable differential.
The air flow is a bit concerning. Perhaps the fan speed needs to be addressed, again mentioned by beenthere.
Post the heat pump model and serial #.


----------



## dohat2 (Jan 29, 2021)

Indoor AIr Handler Unit Model - BVA-36WN1-M20 Model Number 8733952440 208 volts
Condensing Unit Model BOVA-36HDN1-M20G Model Number 8733952437

Does anybody have thoughts on opening the side panel up for greater cfm and if boiler room is a good place to take in so much return from?

Thx


----------



## beenthere (Oct 11, 2008)

Default blower setting is tap 4. Set it to tap 5.

You turn off power. Open blower panel(thats the top panel). On the blower motor, you will see a series of slots numbered from 1 to 5. Pull the wire out of 4, and put it in 5. Close panel, and turn power back on. System will start to operate in 5 minutes after power is turned back on.


----------



## beenthere (Oct 11, 2008)

Post pic of side panel You are talking about.


----------



## dohat2 (Jan 29, 2021)

I do have the manuals in the basement but prefer reading them clearly and zooming in on my computer. On this site, how should I be entering the model numbers - it's not accepting BVA-36WN1-M20 or 8733952440








Owner Manuals | Bosch Home Appliances


All answers in one place: The Bosch Service Assistant conveniently brings all support options as well as tips and tricks for enhancing and maintaining a specific home appliance together in one easy-to-use overview.




www.bosch-home.com


----------



## dohat2 (Jan 29, 2021)

I posted the side panel view here and btw in the above pics, you can hit the right arrow on each picture (there are 7 pics in total). He asked me to remove the side panel you see in the red box as he thinks that'll yield greater cfm. It's supposedly held only by a screw on the top along with sheet metal tape I'm a little uncomfortable doing that as that side panel is facing the rest of the boiler room


----------



## beenthere (Oct 11, 2008)

That will probably effectively prevent you from drawing any return from the first floor.

PS: On your air handler, you set dip switch 1-3, to 1 off, 2 off, 3 on, to run on high speed.


----------



## HVACnut (Jan 25, 2021)

To answer one of your questions, yes the heat pump was in defrost mode when you noticed cool air coming from the vents and the outdoor unit fan was off. What happens in defrost is the direction of the refrigerant changes so that the outdoor coils get hot (to melt any frost) and the indoor coil gets cold (just as if you have it in AC mode)

Now, one of the uses of the aux heat is that it will come on during defrost to keep the indoor air that's blowing warm.


----------



## user_12345a (Nov 23, 2014)

The unit seems to have an accelerated heating/cooling feature that can be enabled - runs a warmer indoor coil in heating mode and colder in cooling mode. Worth a shot.

If your air handler is constant torque and not variable speed, it's probably moving less cfm at a given speed than it should if your ducts are undersized. 

Also, possible it was mis-wired and is only seeing a call for low fan speed.

Aside from these things, you really need to get some aux heat installed. If you have a 100 amp service and can't afford to upgrade to 200 now, you can just get 5kw installed, similar to an electric dryer which should boost heat output by around 17 000 btu/hr.
*Not enough to heat the house by itself, just to supplement and temper the air a little in defrost mode.*


----------



## dohat2 (Jan 29, 2021)

Any idea what dip switch enables the accelerated heating mode? I downloaded the manual but cannot find it

Also looking at the pictures and videos what part of the install does not look correct? In addition should the installer have done a quick test of CFM before recommending this unit.. Were there any other steps missed because I did not see him calculate anything. Lastly is it regular practice to provide a commissioning report after an install? Thanks folks


----------



## dohat2 (Jan 29, 2021)

beenthere said:


> Post pic of side panel You are talking about.


----------



## dohat2 (Jan 29, 2021)

Before I make any change I want to confirm and ensure I'm not doing anything wrong. I am looking to increase the CFM or fan speed? of those four dip switches and which one?

Also I am going to turn the system to off in my thermostat or do I need to turn the actual 220v breaker off as well

Also by looking at the pictures does anybody know if I have the 18 or 36 air handler model size?

Thx


----------



## beenthere (Oct 11, 2008)

Acording to the manual I downloaded. You need to find SW3, to change the blower speed/CFM. The one in the pic is, SW6. But, your air handler could be a newer or older model than the manual I have is for.

You have to turn off the 240 to the air handler.

Also, is there a jumper from Y1 to Y2? If not, make one and connect it. 

According to the pic, switches 1 and 2 both need to be on, to use speed tap 5, when there is a call on both Y1 and Y2.


----------



## dohat2 (Jan 29, 2021)

beenthere said:


> Acording to the manual I downloaded. You need to find SW3, to change the blower speed/CFM. The one in the pic is, SW6. But, your air handler could be a newer or older model than the manual I have is for.
> 
> You have to turn off the 240 to the air handler.
> 
> ...


So I'm going to try turning on dip switch 2 and see if it helps. But I don't see hard to make a cable to connect y1 and y2, is that required for changing fan speed or that's for another function? After changing dip switch 2,. I guess I will have to use my hands to feel if I feel a higher air flow right? What's the worst case if we aren't using the right dip switch? I hope nothing much and I can always revert back. I will use a delicate jewelry flat screwdriver to turn the dip switch on If I cannot reach it with my nails


----------



## beenthere (Oct 11, 2008)

A small piece of thermostat wire can be used to make the jumper. Or speaker wire.

Without the jumper, it will NOT run the blower at high speed. But, according to the units diagram, it should still be higher than what you are at now.


----------



## dohat2 (Jan 29, 2021)

Ok I have speaker wire but don't see Y1 or Y2 on that actual board so not sure where to connect. But I'll turn the dip switch 2 to on and see if it makes a difference now


----------



## beenthere (Oct 11, 2008)

Look for a purple wire then. That unit may have wire leads, instead of screw terminals. If so, then the purple wire is Y2.


----------



## dohat2 (Jan 29, 2021)

Folks - sorry for not posting an update. The contractor called early this morning and said he wants to come back and increase the fan speed & also change to a mode which allows for greater heat. At his cost, he will also install a 5kW backup heat. I told him that I don't want this backup heat to operate in anything but defrost mode to avoid nasty power bills and he agreed

1) Does the unit have in-built diagnostics or an event logger whereby you can attach a computer and it'll tell you how often it entered defrost mode?
2) How long does defrost mode typically last when it's 20 outside? From my observations last few days, it comes on every 40-60 mins but only lasts 1-3 mins. My electric provider is installing a smart meter which will give me 1 minute live readings so I guess a 5kW coming on will be enough of a spike that I'll see it in the live report. I don't have any other large-voltage appliances at home that stay on constantly (only washer/dryer once a week). He wants my electrician to change the 220V outlet from 20amp to 40amp
3) Maybe I should invest in a temperature monitoring logger and place it by one of the supply registers. If somebody has a cheap one like 50 bucks or something or an older model, I can look on ebay


Thanks


----------



## beenthere (Oct 11, 2008)

Only having it able to operate during defrost is foolish.

Ask him how long it would take to get a compressor in for your heat pump.

That is how long you would be without heat, unless you get 10KW of aux heat.


----------



## dohat2 (Jan 29, 2021)

Can you explain this statement - Ask him how long it would take to get a compressor in for your heat pump.
I pay 24c/kWh in my area
If I configure backup heat to come on to reach and maintain desired temperature, it's possible it'll stay on for 10 hours a day?
That means 50kwh X .24 = $12
Assuming 8 real cold days during winter months, it's $96 additional for those months
Am I calculating this correctly? $96/month isn't too bad honestly because our winters here are only really jan-march (3 months)

Also should I get 5kWh or 10kWh backup

Thanks


----------



## beenthere (Oct 11, 2008)

The compressor in your heat pump, is not something kept on the shelf at the distributor. So if it goes out, your out of heat, for X days.

Doubtful the aux heat would run 10 hours a day, unless you constantly raise and lower your thermostat setting.

So what is/was your gas rate?

I think you made a poor choice getting a heat pump with those electric rates.


----------



## beenthere (Oct 11, 2008)

Go out to your electric meter now. Write down the KWH reading. Then go out tomorrow night at the same time, and record it again. Then subtract tonight's reading from that. And see how many KWHs your using with your heat pump running 2/47. You can subtract last years daily KWs to know what the heat pump is using.


----------



## beenthere (Oct 11, 2008)

Wild guess, your heat pump running 24/7, is using roughly 19 bucks of electric a day.


----------



## dohat2 (Jan 29, 2021)

I've attached the gas bill here

Well my heat pump is going to be on in the winter so am I going to be paying 19 x 30 = $570/month ? ouch that's extremely high


----------



## dohat2 (Jan 29, 2021)

2 more quick questions
1) when the contractor comes tomorrow, is there an easy way for him to measure cfm of return air on the 1st floor - I don't see much air flow there
2) Will the increase of fan speed and this high heat mode he talked about going to have a substantial effect on my power bill

Thx


----------



## dohat2 (Jan 29, 2021)

two new gas bill attachments


----------



## zootjeff (Jul 11, 2007)

dohat2 said:


> Folks - sorry for not posting an update. The contractor called early this morning and said he wants to come back and increase the fan speed & also change to a mode which allows for greater heat. At his cost, he will also install a 5kW backup heat. I told him that I don't want this backup heat to operate in anything but defrost mode to avoid nasty power bills and he agreed
> 
> 1) Does the unit have in-built diagnostics or an event logger whereby you can attach a computer and it'll tell you how often it entered defrost mode?
> 2) How long does defrost mode typically last when it's 20 outside? From my observations last few days, it comes on every 40-60 mins but only lasts 1-3 mins. My electric provider is installing a smart meter which will give me 1 minute live readings so I guess a 5kW coming on will be enough of a spike that I'll see it in the live report. I don't have any other large-voltage appliances at home that stay on constantly (only washer/dryer once a week). He wants my electrician to change the 220V outlet from 20amp to 40amp
> ...


I would recommend getting some “sensorPush” sensors. They have a great user interface app for monitoring HVac. I have one on my return and supply ducts to monitor my system..


----------



## HVACnut (Jan 25, 2021)

We have a more basic heat pump than you and our Aux heat only comes on during defrost (defrost last 10 min at most) and if we increase the house temp setting by more than 2 degrees. Even then the aux does not run the entire time we increase the temp. It supplements the heat pump for 1-2 min, then the aux shuts off and lets the heat pump alone finish raising the temp.

We also had a new aux heat strip installed (the old one was not working for awhile). We have a smart meter and I can check my electric use daily. I've seem maybe an increase of usage of 3-4KW each day since having the aux heat working.

Since you have an advance unit, I suspect you can tell the unit to only use the aux heat to help your heat pump when the temps outside are low (like in the 20's) but to otherwise not use the aux heat. They call it "lock out"

My advise ( but I'm no expert) is use the aux heat during defrost (as you plan) and have the installer adjust the setting to lock out the Aux heat when outdoor temps are above 25F.


----------



## beenthere (Oct 11, 2008)

Just the cold months.

Did you do the meter readings like I said.

If you have a smart meter, you should be able to go online and see your usage.


----------



## dohat2 (Jan 29, 2021)

Funny thing is after 4 months of waiting, my coned smart meter install date is Thurs. I assume I'll be able to see a spike in the smart meter live so when aux heat comes on, I'll check thermostat and then check my live energy usage
Will thermostat show 'heat is on' or something like 'aux heat is on'

Also, is there a simply way to check cfm at hvac return air on 1st floor? I don't feel much in there and we had asked him that we want that return to work well


----------



## beenthere (Oct 11, 2008)

At your post electric rate, and the $1.24 per therm for your gas bill.

The COP of your heat pump, needs to be 4.54 to be as cheap as nat gas with an 80% efficient furnace. 

Your heat pump only reaches that COP at outdoor temps of 58°F and warmer. 

Don't know how your electric company will work it. But mine, I can't see instant use. I can see yesterday and earlier, but not time of use.

Did you request a heat pump, or did the contractor talk you into it.


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Funny thing is after 4 months of waiting, my coned smart meter install date is Thurs. I assume I'll be able to see a spike in the smart meter live so when aux heat comes on, I'll check thermostat and then check my live energy usage
> Will thermostat show 'heat is on' or something like 'aux heat is on'
> 
> Also, is there a simply way to check cfm at hvac return air on 1st floor? I don't feel much in there and we had asked him that we want that return to work well


An anemometer can check the CFM at a return. A proper working return will have very little a movement feeling.

Also, have him double check the CFM setting of the blower. You want at least 1150 CFM.

Most thermostats, will display when aux heat is on.


----------



## dohat2 (Jan 29, 2021)

The contractor said this is the way to save money; I didn't have time to quickly research as this was an emergency install

Also in the past we barely used AC in the summer months but tired of sweating it out. We do plan to use it quite a bit this upcoming summer in july & august. Do you think it'll sort of level off with this?

Thx


----------



## dohat2 (Jan 29, 2021)

So what should I have him set the backup heat to? Ability to come on anytime temperatures fall below 40 ?

Thx


----------



## Missouri Bound (Apr 9, 2011)

Your heat pump will use the aux. heat whenever the heat pump itself isn't able to bring the room temperature up in a set period of time.
The defrost aspect uses the same heat, but goes on when the heat pump is defrosting to counter the cold air blowing during the defrost cycle.
Usually the defrost cycle happens when the outside temperature is in the mid 30's.
The heat pump should have factory specs that should be adhered to when setting up the unit.
The ONLY time the aux. heat should come on is when the heat pump can't keep up, or when the unit is in defrost.
If you don't setback the thermostat, which isn't ever advised for a heat pump unless you are away for over 24 hours, the heat pump should keep up unless you have doors or windows open or are in the middle of an extreme cold snap.
My aux heat has only come on a few times in 15 years when it is below zero with a strong wind.


----------



## user_12345a (Nov 23, 2014)

With your type of air handler, the airflow can be determined by checking static pressure and referencing it to the speed tap being used. manometer and tubing/tips -> cheaper than anemometer.

They need to make sure it's actually running at high speed, turn on accelerated heating/cooling, and determine airflow. 

You need all the capacity you can get.

A heatpump was a very poor choice. 

--------------
The aux heat is temperature, not time activated.
The thermostat either waits until it drops 1 to 2F below the setting or monitors rate of change and brings on aux heat when it can no longer keep up.

In a climate with hot summers and a a/c sized large, the need for aux heat may be minimal -> more north, I would it expect a heatpump to use quite a bit of aux heat.


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> The contractor said this is the way to save money; I didn't have time to quickly research as this was an emergency install
> 
> Also in the past we barely used AC in the summer months but tired of sweating it out. We do plan to use it quite a bit this upcoming summer in july & august. Do you think it'll sort of level off with this?
> 
> Thx


I would lock it out at 35°F outdoor temp.

Yes, many people in an emergency situation don't think to ask for proof. 

Unfortunately, you will be paying the price. At 22°F, the heat pump is costing you roughly 2.73 times what an 80% nat gas furnace would cost to heat your house to 70°F And your heat pump isn't even reaching 70°F indoor temp.

I would suggest talking to the contractor about his misleading you. And see if you can work out a deal to get full price back. And that amount be put towards a gas furnace with central A/C installed in its place. 

A heat pump just makes no sense in your area with your utility rates.


----------



## user_12345a (Nov 23, 2014)

Can keep the heatpump for cooling, install the coil on top of a gas furnace. edit: but then, he wouldn't be able to reuse the air handler. you can get a coil for that hp separately.
It's wise to get a 90%+ furnace in a cold climate.


----------



## beenthere (Oct 11, 2008)

user_12345a said:


> Can keep the heatpump for cooling, install the coil on top of a gas furnace.
> It's wise to get a 90%+ furnace in a cold climate.


Why keep an extremely high expensive heat pump, only to use it for cooling only. When he might be able to get the full money back on it, and put that towards a cooling only condensers, and toward the furnace.

Your way, he'll end up with a 20 thousand dollar gas furnace and A/C.


----------



## user_12345a (Nov 23, 2014)

I agree, if he can get the money back on it, it's obviously better.
Funny thing - it was my understanding this particular unit isn't super expensive for a variable, pricing similar to a 2-stage hp with hps not being much more than straight cool. $15k seems steep to me but didn't comment on it as pricing varies considerably, perhaps he's in a super expensive area.


----------



## beenthere (Oct 11, 2008)

user_12345a said:


> I agree, if he can get the money back on it, it's obviously better.
> Funny thing - it was my understanding this particular unit isn't super expensive for a variable, pricing similar to a 2-stage hp with hps not being much more than straight cool. $15k seems steep to me but didn't comment on it as pricing varies considerably, perhaps he's in a super expensive area.


He is in a high cost of living area.


----------



## dohat2 (Jan 29, 2021)

14k in NYC but that seems steep too because I saw the indoor & outdoor units online for 5k total. The two guys installed the whole system in 1.5 days so the labor part of this is 8k. Anyways, I'll have more time in the future to do the right thing for my attic unit. I'll be hard to return anything given most of the cost is labor and not the material. If my power outage spikes up and backup heat comes on too often, I wonder if Bosch sends its own people to make an assessment

What my concern now is also how much more my electric bill is going to spike up to. With my gas furnace, the air blower still used electricity and when under 30 outside, it'll come on every 10 mins, stay on for 3-4 min and turn back on and keep repeating that cycle


----------



## beenthere (Oct 11, 2008)

Not until the installer has tried everything tech support recommends. And then if they will come out. They won't tell you much, since your not actually their customer. Your installer is there customer.

Even still, Bosch's people aren't going to be able to make the heat pump produce more heat. But they will tell you and the installer, you need aux heat.

You can expect large electric bills. February and March bills could be 600 plus.


----------



## dohat2 (Jan 29, 2021)

Does Bosch actually take product back in such a situation and is the return policy 30 days or something?

Also for the 2nd floor, what gas-powered variable unit would you advise for replacement? That fan motor on our 2 ton unit is going old and I suspect it may not last too long. I would like variable because currently, it comes on, stays on only for 3-4 mins delivering a big blast of heat and then off for 10 mins so at night which isn't great for comfort. Thanks


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Does Bosch actually take product back in such a situation and is the return policy 30 days or something?
> 
> Also for the 2nd floor, what gas-powered variable unit would you advise for replacement? That fan motor on our 2 ton unit is going old and I suspect it may not last too long. I would like variable because currently, it comes on, stays on only for 3-4 mins delivering a big blast of heat and then off for 10 mins so at night which isn't great for comfort. Thanks


No, Bocsh won't take it back. The contractor might, since he should have known he was selling you a unit that isn't practical for your area with its electrical rate.

Your upstairs unit is over sized, so you need a furnace sized to the actual load. Plus, you don't want more than a 2 stage unit. It can have a variable speed blower. But, DO NOT GET A MODULATING FURNACE. In an attic install with ceiling registers. When a mod furnace runs in lower firing rates. The rooms further away won't get much heat. And then those rooms will be too cold.


----------



## user_12345a (Nov 23, 2014)

Fan motors on older furnaces aren't expensive, and if the furnace is still good otherwise, I would not scrap it due to a bad blower motor.

With the ducts in the attic, even a 2-stage furnace could increase the fuel consumption/reduce comfort due to the lower blower speed and velocity when on low fire.
Not all 2-stage furnaces are like this, some have the low heat airflow only 10 to 15% lower than high heat airflow.

Properly sized single stage may be the way to go. Attic duct systems are lousy for energy conservation but short of spending lots of money insulating the roof deck, you're pretty much stuck with it.


----------



## dohat2 (Jan 29, 2021)

ok btw for the downstairs unit, is there another kind of backup heat that's not as costly to run as the 5kwh electric strip? There is some space left in the boiler room but not enough to put a full furnace. Thanks


----------



## beenthere (Oct 11, 2008)

Yes, hydronic. A wall hung boiler can be installed.

You need a min of 10 KWs of six heat. If you keep heating sigh the heat pump.
Wall hung boiler, hydronic coil, venting, gas piping, water piping and control wiring might only be between 8500 and 9800 bucks.


----------



## user_12345a (Nov 23, 2014)

Boilers aren't cheap!


----------



## dohat2 (Jan 29, 2021)

Currently the humidifier aprilaire 700 is allowed to control and turn on the fan of the heat pump. Do you think this, in any way could interfere with the heat pump heating the home? The contractor wants to set it in a way that the humidifier will only be able to stay active when the heat is on but I suspect that me not be enough humidity in this old home

Thx


----------



## dohat2 (Jan 29, 2021)

Also is the 5kwh configured with a certain number like come on only if it hits 35 outdoor temperature? Thx


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Currently the humidifier aprilaire 700 is allowed to control and turn on the fan of the heat pump. Do you think this, in any way could interfere with the heat pump heating the home? The contractor wants to set it in a way that the humidifier will only be able to stay active when the heat is on but I suspect that me not be enough humidity in this old home
> Thx


If it were to interfere with heating the house when the heat is not on. Then it would interfere with heating the house when the heat is on.
So no, that won't interfere with heating the house.



dohat2 said:


> Also is the 5kwh configured with a certain number like come on only if it hits 35 outdoor temperature? Thx


First, if you only get 5 KW of strip heat, instead of 10 KW, your heating bill will exceed 800 bucks a month, when the temps are below 20. 

Your basement and first floor are losing about 800 BTUs per degree under 65°F outside temp. So when its 0°F outside, your heat pump will only provide 22,600 BTUs of the roughly 52,000 BTUs you need. 5 KW of aux will only provide an additional 17,065 BTUs of heat. For a total of 39,665 BTUs. Leaving you short 12,335 BTUs short of heating your house to a set point of 67. Or in other words, your basement and first floor will only be 55°F, while the heat pump and 5 KW of aux heat, use 7.77 KWHs an hour. Or, 186 KWs in a 24 hour time period, and your place is cold.

Your so worried about being frugal on heating operating cost, your going to cost yourself a lot of money.

Yes, a GOOD thermostat can be set to lock out the aux heat when the outdoor temp is above X degrees.


----------



## timberguy (Jan 15, 2021)

HVACnut said:


> Dohat 2, you need aux heat for a heat pump to work up north. We live in SC and even need it here where temps at worse are in the low 30's. It will help get the temp up when you raise the thermostat, and you need it to keep the air warm when your unit goes into defrost (or it will blow cold air)
> 
> Are you sure it does not have it? What are the choices listed on your thermostat? Just AC and Heat? No Aux heat listed?


We have newer Samsung system--single pump outside, two (2) indoor units-- in new 4500SF home installed 2018. NO heat strips as in systems we've had before. Very efficient. Of course this house is highly insulated. And it has gotten close to Zero out here in the boonies.


----------



## dohat2 (Jan 29, 2021)

timberguy what is your cents/kwh cost and what's your rough electric monthly bill in the winter months

Thx


----------



## beenthere (Oct 11, 2008)

timberguy said:


> We have newer Samsung system--single pump outside, two (2) indoor units-- in new 4500SF home installed 2018. NO heat strips as in systems we've had before. Very efficient. Of course this house is highly insulated. And it has gotten close to Zero out here in the boonies.


Your comparing a mini split system to a conventional system.


----------



## roughneck (Nov 28, 2014)

dohat2 said:


> timberguy what is your cents/kwh cost and what's your rough electric monthly bill in the winter months
> 
> Thx


Not comparing apples to apples. It’s a different style system.


----------



## dohat2 (Jan 29, 2021)

the scariest thing is the possible $800 bill - beenthere how did you come up with that number? I plan to keep my heating to 68 on the 1st floor


----------



## beenthere (Oct 11, 2008)

I looked at the spec sheet for your unit. And then based on the outdoor temp and that it wasn't maintaining set indoor temp. Figured out the KWHs it will use running 24/7.

In your case. 10 KW of aux heat will save you money.

But, you should follow my advise and push for him to take out the heat pump, and install a gas furnace again. 

So what is your current outdoor temp, and what indoor temp is it maintaining.


----------



## dohat2 (Jan 29, 2021)

outdoor 40, during the day it's maintaining the 68 without the backup heat and at times, the unit turned off too


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> outdoor 40, during the day it's maintaining the 68 without the backup heat and at times, the unit turned off too


So basically under 40 outdoor temp, its not going to shut off. 

So at 37°F outdoor temp, its going to use 2.9 KWs an hour of run time. Which will be 24/7. 24x2.9=69.6 KWs on a relatively mild day. 69.9x30=2,088KWs if it stays 37°F outside the entire month. Which at your electric rate is $501.12 And the first floor won't even reach 68 degrees.

From 17 to 27° outdoor temp, it uses even more electric, and provides far less heat. And its those cold days that will push you to up to 800 bucks for the month, and not be even close to 68 degrees on the first floor.


----------



## beenthere (Oct 11, 2008)

You NEED the 10 KW of aux heat.


----------



## user_12345a (Nov 23, 2014)

How would straight aux heat save money when the heatpump's cop should always be well above one? unless it's the defrost cycles, in which case it doesn't make sense to run the heatpump.

Aux heat is for comfort and it would run continuously with aux to begin with.

Unless I'm missing something.


----------



## beenthere (Oct 11, 2008)

Never said to run it on emergency heat.


----------



## dohat2 (Jan 29, 2021)

Does your 2.9kwh/number include aux heat? If I turn off aux heat and insulate and air seal the home so that the heat pump can maintain temperatures by itself, what would that 2.9 number change to



Thx


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Does your 2.9kwh/number include aux heat? If I turn off aux heat and insulate and air seal the home so that the heat pump can maintain temperatures by itself, what would that 2.9 number change to
> 
> 
> 
> Thx


No, 2.9 KW is what just the heat pump and air handler blower use. 

Whatever the KW rating of aux heat is. Is what KW the aux heat draws.

The 2.9 KW remains the same at the same termps no matter how well sealed or insulated a place is. Just the amount of on time is reduced, and the amount of off time is increases.

Unless your willing to spend 30 to 40 grand to insulate, seal, and then add mechanical insulation. Your not gonna be able to heat your place with the heat pump alone.

PS: How open is your first floor to the second floor. And what temp do you keep the second floor at.


----------



## dohat2 (Jan 29, 2021)

The second floor is 62 all the time and the attic traditional furnace unit supports it


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> The second floor is 62 all the time and the attic traditional furnace unit supports it


And how open are the 2 floors to each other.


----------



## dohat2 (Jan 29, 2021)

I am sorry I did not answer your last question fully. Even though this is a 100-year-old house it has very large entrances to each room without any doors. The staircase connecting between the first and second floor is right in the middle. There is a large return on the second floor right over the staircase as well and the only rooms where we close doors are the three bedrooms on the second floor. I am curious about this question - are you thinking of anywhere where we can leverage the second floor furnace to better heat the first floor? From what I understand cold air always moves to warm air. How would you really like to understand what you are thinking


----------



## dohat2 (Jan 29, 2021)

Correction - we only close the bedroom doors at night to keep away the noise from the kids. The doors are100 years old and there is one inch at the bottom of each store which is open


----------



## beenthere (Oct 11, 2008)

Your second floor cold air is dropping to your first floor. During the day, when the second floor isn't being used basically. Set the thermostat to 72. You won't have as much cold air coming down to the first floor. And the ceiling of the first floor, basically will stop losing heat. The heat pump will handle the lower load a little better.

But, you will still need that 10 KW of aux heat installed.


----------



## beenthere (Oct 11, 2008)

Most places that have 2 systems with 1 being gas heat and the other being a heat pump. Have the gas heat on the fisrt floor, and the heat pump on the second floor. Since the heat pump doesn't have as much load for heat then.


----------



## dohat2 (Jan 29, 2021)

The contractor already installed five kilowatt heat at his own cost but will not agree to 10 kilowatt. He also enabled high efficiency heating and change the speed to 3-5 modulating. In addition he fully connected the first floor return duct to the unit (before there was a partial opening to get some return air from the basement too). We are seeing a greater air flow and my tissue paper is actually sticking to the return duct on the first floor. so far it is staying at 68 with outdoor temperatures between 35 and 40 and I have not seen auxiliary heat come on unless I move the thermostat to 70 or higher. 

I am assuming that you would like me to change the second floor thermostat to 72 so it's 4 degrees warmer than 1st floor?


----------



## beenthere (Oct 11, 2008)

72 because the cool air falling from the second floor, will then be 68 to 70°.

5 KW is not enough. You should have offered to pay for the difference in price between 5 and 10.

Or, insisted on him ripping out the heat pump, and putting in a gas furnace as it should have been in the first place.

There is NOTHING you can do to make a heat pump cheaper to heat your place than gas. Because your electric rate is too high.


----------



## beenthere (Oct 11, 2008)

PS: Is that between 35 and 40 during the day and night, or just day time.


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> and I have not seen auxiliary heat come on unless I move the thermostat to 70 or higher.


A question about that. It is normal for the aux to come on when you move the tstat more than 2°.
After the area warms up 1 degree, does it go off? It should.
If the heat pump can keep it at 68° when 35° outside it should be able to keep it at 70° once it catches up.
Have you tried it?
I think the 5kw probably will not be enough when it is 10 deg. or colder....but you will find out soon.
What exactly did the contractor have to do to install the 5 kw heat strip?
Did he have to make any changes to your circuit or did you have adequate amperage already at the ready?


----------



## dohat2 (Jan 29, 2021)

35/40 during the day. The nights have been 30-35

I had to have the electrician install 40 amps for the 5kw heat. Also I have not tried moving up two degrees and seeing if the oxy turns off after it climbs one degree. I can try that out if you like. so far my approach was keeping it at 68 like it always has been and then comparing next month's electric bill with last


----------



## beenthere (Oct 11, 2008)

If they installed your smart meter Thursday, you can look at your KW usage on Thursday and Friday online.

Or, you can just go read your meter now, and then again in 2 hours, if the heat pump is running now.


----------



## dohat2 (Jan 29, 2021)

The smart meter won't be active for another 10 days according to ConEd but pretty dumb of me do not think of checking the physical meter outside the house for difference. I will check it now and again in the morning and make a calculation


----------



## dohat2 (Jan 29, 2021)

I am not sure I understand all those different numbers and if you guys know it would be nice to get an explanation









Streamable Video


Watch this video on Streamable.




streamable.com


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> my approach was keeping it at 68 like it always has been and then comparing next month's electric bill with last


And that is *exactly* what you should do.
The heat pump is different than the gas heat you had before. It takes longer to recover and doesn't like to be setback. All of the savings can easily go away if you play with the thermostat or set it back for just a few hours. Set it where you are comfortable and see if it keeps up. 
If it can't keep up you can start looking into other ways to insulate your home. If the fan can run continuously, at a lower speed then ramp up when the stat calls for heat it will help circulate.
I do not know if your system is capable of doing that.


----------



## dohat2 (Jan 29, 2021)

I suspect that that the heat pump was not on when I took this video. but at least I can take the same video tomorrow and then calculate the difference in how many kilowatt hours it used


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> I suspect that that the heat pump was not on when I took this video. but at least I can take the same video tomorrow and then calculate the difference in how many kilowatt hours it used


You will need a month of billing before you can get an accurate idea of what its going to cost.


----------



## beenthere (Oct 11, 2008)

Probably not. But tomorrow you should see a big difference in the reading.


----------



## dohat2 (Jan 29, 2021)

Did you guys see the streamable link here and what do the different numbers mean








Streamable Video


Watch this video on Streamable.




streamable.com












Streamable Video


Watch this video on Streamable.




streamable.com


----------



## beenthere (Oct 11, 2008)

Might need an electrician to explain the numbers. I just go online to see my usage.


----------



## dohat2 (Jan 29, 2021)

Shouldn't the backup heat come on as soon as the unit starts defrost cycle? I am still getting cold air at the defrost cycle


----------



## beenthere (Oct 11, 2008)

5KW of strip won't give you warm air during defrost, on a 3 ton heat pump.

Your heat pump in defrost will cool the return air by 20 degrees plus or minus a couple. At 1150 CFM, 5 KW of strip heat will only warm that air by 13 degrees.

So 68-20+13=61 degrees leaving the air handler. 

If its moving more than1150 CFM, then the air will be cooler yet.

So what is your meter reading this morning.


----------



## dohat2 (Jan 29, 2021)

Streamable Video


Watch this video on Streamable.




streamable.com




Here is the video from this morning


----------



## beenthere (Oct 11, 2008)

I could be wrong, but looks to be 46 KWHs. $11.04

How cold did it get last night.


----------



## dohat2 (Jan 29, 2021)

Yesterday's video was about 42 and this morning's video 32 and the average was right in the middle of that


----------



## beenthere (Oct 11, 2008)

So between 27 and 32 KWs for the heat pump, and between 8 and 13 KWs for the aux heat. $11.04

Same amount of heat from an 80% efficient gas furnace at your rates, $5.94


----------



## beenthere (Oct 11, 2008)

Same amount of heat from a 95% efficient gas furnace at your rates, $5.05


----------



## dohat2 (Jan 29, 2021)

Streamable Video


Watch this video on Streamable.




streamable.com




Here is the latest video with the heat pump on


----------



## dohat2 (Jan 29, 2021)

beenthere you were right - the 5kw backup heat coming on during defrost is only providing 60 degree cold air. If I get him to replace with 10kw, will I have to change the electric power again or the 220V 40amp circuit should do it?

Thanks


----------



## roughneck (Nov 28, 2014)

You’ll have to change it to a larger circuit. 40A will not be enough for 10kw of electric heat. 
This will also increase your electric bill even more over what a gas furnace would have cost to run.


----------



## beenthere (Oct 11, 2008)

If they only ran a 8 gauge wire, it will have to be increased in size, along with the breaker.


----------



## dohat2 (Jan 29, 2021)

guys - I'm going to talk to the contractor to replace the heat pump with a high-efficiency furnace. Of course I'll need a unit that's also used for cooling like the last one. Can somebody recommend something in 3 ton capacity which is what I had before? Maybe something that's able to modulate between 2-3 tons would be good too since I am going to air seal, insulate the attic & basement & get new entry doors

Thanks


----------



## beenthere (Oct 11, 2008)

All brands have a modulating A/C. However, Bocsh is probably the least expensive.

Plus, you don't need to use their thermostat or furnace for it to work properly.


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> guys - I'm going to talk to the contractor to replace the heat pump with a high-efficiency furnace.


I just have to ask.....why did you decide on a heat pump in the first place? Was it your idea or did someone talk you into it?
Now I have a heat pump, the top of the line Lennox. I had it installed about 4 years ago.
It is a 3 ton, had a humidifier. It has a variable speed compressor.
No electric had to be changed since I replaced a Goodman that failed.
It cost me about $9,000.
They started at 8 in the morning and the last guy (owner) left about 4 PM.
The lowest price unit quoted, still a Lennox was about $4000.


----------



## beenthere (Oct 11, 2008)

Also. DO NOT fall into the I need a big furnace trap. You need one properly sized for the area it serves. 

Too big, and you'll get duct/air noise, and the furnace will be locking out on its high limit, giving you a cold house.

You probably need at most, something like a 60,000 BTU input 95% furnace. That would give you 57,000 BTUs output, and at 1055 CFM, a temp rise of 50°F.

You might want to spring for a 2 stage unit. One that the thermostat controls staging. This will increase comfort on the first floor. As it will have longer run times, and help to counter the cool air coming down from the second floor, from giving you a cool draft feeling, and short cycling.


----------



## dohat2 (Jan 29, 2021)

guys - contractor hasn't gotten back to me but I've been looking up datasheets on bosch.com. It seems this is the 60k btu unit - does anybody know what these typically retail for?
BGH96M060B3A

Is there anything apart from the furnace that I need to purchase or it comes with air handler/blower and the air-conditioning part?

Also it says here that these units pair with the IDS heat pump? Does that mean I don't have to replace the outdoor unit?


https://www.bosch-climate.us/files/Bosch_96_Furnace_Submittal_Sheet_01.2019_US.pdf



Thx


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> guys - contractor hasn't gotten back to me but I've been looking up datasheets on bosch.com. It seems this is the 60k btu unit - does anybody know what these typically retail for?
> BGH96M060B3A


I don't know the retail but I (you) can buy one for about $2000
The AC coil would be about an additional $500.
Maybe $150 for delivery.









Bosch BGH96M060B3A 96% 60k Btu Gas Furnace


Veteran Owned and Operated HVAC Supply Warehouse; The BGH96 Furnace’s two-stage gas valve switches between high and low fire settings to meet load demands, allowing for more efficient operation than single stage technology. This means enhanced comfort and energy savings for homeowners by...




skipthewarehouse.com


----------



## beenthere (Oct 11, 2008)

You don't need, or want the 5 ton blower model. The 60,000 BTU input, 3 blower model, and then a case coil to connect A/C.


----------



## user_12345a (Nov 23, 2014)

the furnace doesn't have to be bosch.


----------



## dohat2 (Jan 29, 2021)

isn't one benefit to go with a bosch furnace that it pairs with Bosch IDS heat pump? Also will 60k furnace be sufficient for basement & 1st floor. I had this model before - g8c10020mud12j and also attached a picture. Basement & 1st floor is roughly 1500sq feet and 2nd floor is roughly 600sq feet. I do plan on blown-in insulation in the attic and basement rim joists in April and like I mentioned before, basement unit serves basement & 1st floor while attic unit (still furnace) serves 2nd floor

Also here is the latest video which is 5 days from my streamable link in post 115. Wondering if somebody can tell how much kwh I've used in 5 days which should be a good indication of what I'll use in a month








pxl-20210211-201957499_WlVJh0Gc_wOxt


Watch "pxl-20210211-201957499_WlVJh0Gc_wOxt" on Streamable.




streamable.com




Thanks


----------



## beenthere (Oct 11, 2008)

A 95% efficient 60,000 Input 57,000 BTU output, will be plenty.. Remember, your heat pump with 5 KW of electric aux heat would only have been a combined 39,665 BTUs output at 2°F outdoor temp.

Your old furnace was grossly over sized.

The BOVA is designed to be compatible with any furnace brand.


----------



## beenthere (Oct 11, 2008)

Looks like 695 KWs to me.


----------



## dohat2 (Jan 29, 2021)

My thermostat options show heat, emergency heat in options but don't see an option not to use emergency heat. Any idea if it's possible? at this rate, I'm looking at a $1000 bill this month just like you predicted. Contractor hasn't called me back


----------



## dohat2 (Jan 29, 2021)

Also does an indoor Bosch furnace actually pair with the outdoor IDS unit and is better to stay with bosch because of that reason? If the current contractor doesn't call me back, I'll have to call a new hvac company to do this


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> My thermostat options show heat, emergency heat in options but don't see an option not to use emergency heat. Any idea if it's possible? at this rate, I'm looking at a $1000 bill this month just like you predicted. Contractor hasn't called me back


Nope. Emergency heat comes on when your t-stat can't keep up.
The only way to keep it from coming on is to disconnect it at the t-stat.....and you really don't want to do that.


----------



## dohat2 (Jan 29, 2021)

Ok I will give contractor 2-3 days to respond but if not I'll call another hvac company. This has obviously been an install from hell for me

Do I need to get any manual J, S, D etc done before this or you guys confident that the 60k furnace would suffice? Also please comment on this question if you can:
"does an indoor Bosch furnace actually pair with the outdoor IDS unit and is better to stay with bosch because of that reason. Would they have to change only the indoor unit"


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> Do I need to get any manual J, S, D etc done before this or you guys confident that the 60k furnace would suffice?


OK, here's my opinion on that.
When you replace a furnace that has been operating successfully and heating and cooling properly you can *usually *replace it with one of the same output.
I know that you will have some or many that disagree with me. If is often said that the old one may have been too big, too small, etc.
But I believe that if a unit with a certain size output served you well before you replaced it that there is no reason to re-invent the wheel.
New construction.....certainly you need a valid calculation to know the starting point.
Here's my calculator.


----------



## dohat2 (Jan 29, 2021)

The unit before which we had for 5 years since we purchased the house was not working great. It used to cycle on and off during both the heating and cooling season quite a bit. Even if it was 30° outside the heating would come on for about 5 minutes and then be off for another 5 minutes and then come back on. Same thing in the summer season where it would cycle on and off and would never be able to dehumidify the house but that is perhaps because it's a leaky house which we will be fixing this spring


----------



## roughneck (Nov 28, 2014)

Those cycling numbers sound like the system was in fact oversized.


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> s because it's a leaky house which we will be fixing this spring


And that could present a problem. Any calculation has to be made on the current condition of the space. Window r-value, insulation value, type of construction, etc.
Older homes never used calculations.....and many didn't have insulation. Energy was cheap, just buy the biggest system you could afford.
But many systems modulate both the heat and air-conditioning. In other words they supply what you need. Many go that route thinking that it will adapt if it is too big.
The biggest problem with oversizing is overheating, short cycling and in the summer not running long enough to properly dehumidify. 
I think that the biggest part of your issue is trusting a contractor who didn't have your best interests being the primary consideration.


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> My thermostat options show heat, emergency heat in options but don't see an option not to use emergency heat. Any idea if it's possible? at this rate, I'm looking at a $1000 bill this month just like you predicted. Contractor hasn't called me back


In order for emergency heat to come on. You have to switch the option to emergency heat.Then the heat pump won't run. And only the electric resistance heat will come on.

Your thermostat may or may not have the ability to lock out the aux heat. Don't remember what brand and model thermostat you have.

So you have decided better a cold house, and lower electric bill is what you want.

Have you tried setting your second floor to 72, so the cool air from it, doesn't keep your first floor heat running as much.

A Bocsh furnace won't work any better with the BOVA, than a York furnace will.


----------



## dohat2 (Jan 29, 2021)

I did increase the heat on the 2nd floor 2 days ago; I still do see the heat pump stay on 98% of the time with the aux heat on all night into the early morning hours and then maybe 30% of the time during the day. Unfortunately I had to reduce the heat - I can't afford to pay a $1000 bill and my plan right now is to quickly replace within the next 1 week

Per the earlier comments, should I still simply go for a 60k 2-stage furnace or should I actually pay a qualified professional to come do the manual j, etc calculations for me? Fact is today there are insulation pads in the attic, etc but nothing compared to what blown-in insulation with air sealing would provide which is my April project. If Manual J calculation would cost $300-$400 it may be worth the investment given how much money I've poured down on my hvac in the last 5 years

Thanks


----------



## beenthere (Oct 11, 2008)

A Manual J load calc won't hurt. But doubtful it will show anything smaller than a 60,000 input furnace. 

More insulation in the attic will help the second floor unit. 

The cost of the gas furnace to keep the second floor warmer isn't increasing your heating cost, when it decreases the amount of time the heat pump runs.

Running all night long shows you needed a 10 KW strip heat kit, not just a 5 KW.

Nice thing about a 60,000 BTU 95% efficient furnace is that when you control staging with the thermostat, Even if you made enough improvements to reduce the heatloss to only need a 40,000 BTU, the 60,000 2 stage would not be over sized in first stage, and would still provide nice comfort.

An 80,000 BTU, whether single or 2 stage would be too big.


----------



## dohat2 (Jan 29, 2021)

guys - 

96% efficient 2 stage furnace would require pvc venting and I know my old furnace used to go out the 100 year old chimney. Instead of going to the chimney in the past, can an hvac contractor simply go out the side of the house for a cheaper installation cost?
my ductwork is only 6" and don't think it's very efficient. It's possible there are some unsealed parts to in but I can't get to it since it's the drywall. Everything the last homeowner did was of low quality. Will this impact your 60k btu recommendation for heat?
also what size coil should I get to pair with my heat pump outside? As stated in the 1st thread the outdoor unit is 
BOVA-36HDN1-M20G Model Number 8733952437 and it can modulate between 2-3 tons


Thanks


----------



## beenthere (Oct 11, 2008)

Nope, still 60,000 BTU input 5% furnace. It can be vented out the side of the basement.

What ever Bocsh 3 ton coil that matches the outdoor unit.


----------



## dohat2 (Jan 29, 2021)

I was wondering about the summer months - would the heat pump be more expensive to run vs a traditional coil or about the same?

Thanks


----------



## beenthere (Oct 11, 2008)

The same as any A/C of the same efficiency rating.


----------



## dohat2 (Jan 29, 2021)

Update - the contractor is working with bosch to return these units and provide furnace/heat pump - he said those units cost a little more which I don't know why (they are more traditional units I thought). I told him I would rather have a 96% 2-stage vs a 80% efficient unit since it's a new install and he told me it'll take pvc pipes through the side wall (for both venting and a fresh air intake into the system). He did say that electric usage for cooling will be higher than the heat pump but even if that's the case, my cooling days are only about 30 vs 120 for heating

Also I found the labels for my attic unit and it seems oversized:
Indoor furnace - Model G8C10016MUC12H Serial W0H6807785 - 80% efficient 80k BTU output heating
Outdoor condenser - Model GSC130241FD 2 ton 13 seer

Also, the heat pump replaced this indoor furnace - Model G8C10020MUD12J (80% efficient 80k BTU output heating). I don't have a picture of the old outdoor condenser

Quick question for you - you said the below on post# 67. Do you know the average COP for IDS 2.0 at temps around 35 degrees outdoors which means indoor-outdoor difference would have to be about (70-35) or 35 degrees

_The COP of your heat pump, needs to be 4.54 to be as cheap as nat gas with an 80% efficient furnace.
Your heat pump only reaches that COP at outdoor temps of 58°F and warmer._



Thanks


----------



## beenthere (Oct 11, 2008)

Not off the top of my head. But no where near the 4.54 to break even with nat gas at 80% efficient.


----------



## beenthere (Oct 11, 2008)

Make sure he doesn't over size you and put in a 80,000 95%.


----------



## Bob Sanders (Nov 10, 2013)

dohat2 said:


> _The COP of your heat pump, needs to be 4.54 to be as cheap as nat gas with an 80% efficient furnace.
> Your heat pump only reaches that COP at outdoor temps of 58°F and warmer._


That's a pretty open-ended statement to make. It depends completely on your gas/electric pricing and how dependable that pricing is, but 4.54 seems pretty high in any event though.


----------



## dohat2 (Jan 29, 2021)

1.3 per natural.gas therm and 28 cents per kwh in my area. I am including supply and delivery charge in both those counts and also including taxes. I will ask for the 60k heating btu unit but for the coil what should I ask? The outdoor unit is a 2-3 ton modulating unit


----------



## dohat2 (Jan 29, 2021)

Also what should I expect in differences between 80% versus 96% furnaces. I know the supply air is not as hot, anything else? Does it blow with the same speed in the 2md stage? I guess as long as the BTU is sufficient, the new unit should not have a problem reaching my target temperature correct? With the old furnace if it was 35 outdoors and it was 63 indoors and I suddenly moved the target to 68, it would be able to get there in about 45 minutes. Would that be similar with the 96% efficient units as well? 

Also for.the air blower, I guess the default is ECM which means variable fan speed correct?


----------



## Bob Sanders (Nov 10, 2013)

dohat2 said:


> Also what should I expect in differences between 80% versus 96% furnaces.


A higher overall maintenance bill on the 96?
Maybe it's just me but I don't think the ultra high efficiency units save you anything in the end because they do drink up more maintenance money.


----------



## dohat2 (Jan 29, 2021)

Don't they buy you some comfort?.the one stage I have on the second floor blows heat so aggressively for 5mins, then turns off for 15 mins and repeats that cycle. Makes us hot and cold


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Also what should I expect in differences between 80% versus 96% furnaces. I know the supply air is not as hot, anything else? Does it blow with the same speed in the 2md stage? I guess as long as the BTU is sufficient, the new unit should not have a problem reaching my target temperature correct? With the old furnace if it was 35 outdoors and it was 63 indoors and I suddenly moved the target to 68, it would be able to get there in about 45 minutes. Would that be similar with the 96% efficient units as well?
> 
> Also for.the air blower, I guess the default is ECM which means variable fan speed correct?


Air flow will be higher in second stage than in first stage. 

An ECM is not a variable speed motor. They do make variable speed ECM blowers though.

A 60,000 BTU input 80% is only 48,000 BTUs output, a 60,000 BTU input 96% is 57,600 BTUs output.

Won't recover as quick as your old over sized gas furnace did. But, when its staging is controlled by the thermostat, it will provide much much better comfort than your old furnace did.

Not much more that can go wrong with a 96% than a 80%. Neither will work well if installed wrong.


----------



## dohat2 (Jan 29, 2021)

Outdoor heat pump - BOVA-36HDN1-M20G Model Number 8733952437
Since my outdoor model is 2-3 ton modulating, should I ask contractor to go with 2 ton indoor coil instead of 3 tons?

Thx


----------



## dohat2 (Jan 29, 2021)

Guys - spoke to the contractor and he conferenced in the Bosch rep. Instead of going primary on the gas furnace, they recommend doing this

Keep heat pump as primary on my wifi honeywell thermostat but configure it to come on only when outdoor temp is 55+
Keep furnace as secondary heat

Does this make sense and what I should do? Electric rates are going to jump another 4% this year and natural gas has been steady. However, we never know if natural gas will stay low so this flexibility may help. Plus it doesn't seem I have anything to lose here - if my heat pump still turns out to be more expensive than gas even over 55+, I'll simply change the thermostat to have it come on only over 75 degrees which will never occur because my target heating temperatures in winter are always 72 or lower

Thanks


----------



## beenthere (Oct 11, 2008)

Makes no real sense to have the heat pump come on for heat, unless the furnace breaks down on the gas/ignition side.

The couple cents the heat pump might save you when it runs while its between 55 and 65 outside, isn't worth it.

Sorry, but I would have a hard time with any recommendation from the guy that sold you the heat pump without aux heat. And then thought 5 KW of aux would be enough.


----------



## beenthere (Oct 11, 2008)

PS, if the electric goes up another 4%. Then the heat pump won't break even with the gas furnace until its about 58 outside.


----------



## dohat2 (Jan 29, 2021)

Ok but do I have anything to lose if the thermostat can be programmed in whatever way I like - I can set heat pump lockout to 70 degrees and that way, heat pump will never operate. This way I'll be in total control. Maybe 4-5 years down the line, I think about putting some sort of solar panel, etc.if costs come down considerably

If you don't agree, what's your recommendation for me to tell contractor? Simply use furnace for all heating and configure heat pump only for cooling during summer months?

I'm stuck with him unfortunately - at least, he's coming back to replace components with labor at no additional cost to me


----------



## dohat2 (Jan 29, 2021)

Also worst case, can I simply click on 'emergency heat' in the thermostat which will use furnace for all heating?


----------



## beenthere (Oct 11, 2008)

Yes you can simply set the thermostat to emergency heat.

I would just set the thermostat up to control a gas furnace with A/C so that the heat pump is never brought on for heat, and I don't forget in fall that I can't just set the thermostat to heat.


----------



## dohat2 (Jan 29, 2021)

Sorry for so many questions - as I said, I'm stuck with this guy for now nd have to ensure he's doing everything properly. I'm assuming the right way of putting in a high-efficiency furnace is having both a combustion intake vent and an exhaust vent right? I heard there is another pipe in pipe approach - do you know anything of that?

Also can the combustion intake vent and exhaust vent be 1 feet from each other but at the same height of 18 inches over the ground? Or must the exhaust vent be higher? I don't have too much room to play with so can I simply keep a 2 inch vertical gap between the two + 1 feet of horizontal gap?

Thankfully right outside the boiler room side wall, our snow never accumulates there at all because of how it
it's pitched so 18 inches should be fine (we've been here 5 years and been through about 7-8 major snowfalls)


----------



## beenthere (Oct 11, 2008)

The concentric vent you mention, is a termination pipe that the exhaust goes into the middle opening, and the intake connects to a Y port on the pipe. The pipe is larger to accommodate the intake and exhaust volume.

There is also, and vent connector that the 2 pipes can be side by side, but they are connected to a common cover.

If ran as 2 single pipes without the common cover connector, then the exhaust Must be higher than the intake, or it could pull exhaust vapors into the intake pipe and freeze it shut.


----------



## dohat2 (Jan 29, 2021)

So if all I have is 2 in possible between the two pipes it sounds like concentric maybe the better option for me?


----------



## beenthere (Oct 11, 2008)

The exhaust can be elled up 12" above the intake, and then elled again so it points a way from the house.


----------



## dohat2 (Jan 29, 2021)

Thank you for explaining this well. This way both of the winds can come out right next to each other and at the maximum allowable height which is 21 inches and then we can do the double elle for the exhaust


----------



## dohat2 (Jan 29, 2021)

Also roughly calculating how many 90° elbows I have and noting that a 90° elbow adds 5 ft, We are looking at a total length of approximately 40 ft for the exhaust vent and maybe 30 ft for the intake. I hope that's okay

Thanks


----------



## beenthere (Oct 11, 2008)

Length sounds fine. The install manual will have a chart for length with X number ells.


----------



## dohat2 (Jan 29, 2021)

Btw side question - I know the ideas too is rated at 56 decibel but it seems my heat pump has been making more noise after the contractor configured it for high heat mode and increase the fan speed. I used a mobile app this evening and placed it on all the four sides and the highest it measured was 82. I know it's just a mobile app but many of these apps are quite accurate these days

do you think high heat and a high fan speed could cause such a big difference when the unit is rated for 56 DB or something else like some snow or ice has gotten stuck

Thanks


----------



## Missouri Bound (Apr 9, 2011)

How far away did you measure? The standard measurement for HVAC equipment is one meter. (39.37 inches)
And I am sure the factory measurement is taken on the side farthest away from the compressor.


----------



## beenthere (Oct 11, 2008)

The high heat setting is probably increasing noise a bit.


----------



## dohat2 (Jan 29, 2021)

Ok I took the measurement 1 meter away and still getting about 70 decibels. Sometimes, I hear another noise from the machine apart from just the fan

I seem to hear a sound apart from just the fan blades spinning here








Streamable Video


Watch this video on Streamable.




streamable.com





Two different sound tracks taken 2 mins apart. 2nd sound track starts at the 12s mark




__





Vocaroo | Online voice recorder


Vocaroo is a quick and easy way to share voice messages over the interwebs.




voca.ro





Also folks I'm wondering if I should invest in a Honeywell IAQ thermostat to measure Delta-T all the time and alert me when it's off. Do you think this is generally advisable for most homeowners to do? I went through one of the youtube videos and it states that it's constantly measuring Delta-T so can proactively tell you when you are low on refrigerant, have dirty coils, dirty burners, bad igniter, etc. Are all these quite real for the thermostat to identify or it'll simply tell me when the Delta-T is off from its historical readings and then I have to go identify what the cause is. Before spending $600 on parts & labor, I'm wondering if I should simply measure delta-T manually every quarter. I will mostly be using the system in the heating season and will be using AC only maybe 30 days in the summer

Thanks


----------



## beenthere (Oct 11, 2008)

It will only show/tell you the delta is not within the set up temp. 

Unit sounds fine to me.


----------



## dohat2 (Jan 29, 2021)

Still waiting to hear back from contractor about my email about installing a 60k BTU 96% AFUE furnace. I'm curious about one thing - is my 3 ton coil oversized too for the summer months or heat pumps can modulate well? In the past with my 3 ton air coil and traditional condenser outside, it would cycle every 10-15 mins and never be able to bring down humidity

Thanks


----------



## beenthere (Oct 11, 2008)

The BOVA can be set to run at a lower capacity.

Standard single stage can't be set to run at a lower capacity.


----------



## beenthere (Oct 11, 2008)

Plus, with a VS blower, the blower can be set to run at a slower speed/lower CFM to remove more moisture, and with the right thermostat, it can be slowed down even more for high humidity times.


----------



## dohat2 (Jan 29, 2021)

Got it - once the install is done, I'm thinking of ensuring multi-stage furnace works by turning temp up by one degree which perhaps is going to kick in the 1st stage and seeing how much air is flowing through the supply ducts. Then, I can turn temperature up 5 degrees which should kick the 2nd stage and should have a more powerful air flow and higher temperature coming out of supply register right?

Should I buy this device to test my cfm - pretty inexpensive


https://www.amazon.com/Digital-Anemometer-Handheld-Temperature-Backlight/dp/B07V21HQFX/ref=sr_1_1?dchild=1&keywords=HP-866A&qid=1614549742&sr=8-1



Thanks


----------



## beenthere (Oct 11, 2008)

No. Those are actually hard to get a good accurate CFM. You have to take several readings across the register, and then average the readings, and then use the AK/free area of the register to know approximate CFM.

A VS blower will deleiver set CFM at static pressures up to 1".


----------



## Bob Sanders (Nov 10, 2013)

dohat2 said:


> Also folks I'm wondering if I should invest in a Honeywell IAQ thermostat to measure Delta-T all the time and alert me when it's off. Do you think this is generally advisable for most homeowners to do? I went through one of the youtube videos and it states that it's constantly measuring Delta-T so can proactively tell you when you are low on refrigerant, have dirty coils, dirty burners, bad igniter, etc. Are all these quite real for the thermostat to identify or it'll simply tell me when the Delta-T is off from its historical readings and then I have to go identify what the cause is. Before spending $600 on parts & labor, I'm wondering if I should simply measure delta-T manually every quarter. I will mostly be using the system in the heating season and will be using AC only maybe 30 days in the summer
> 
> Thanks


I have the IAQ, and while it was fun at first to read logs, adjust and play around with efficiency, I fast lost patience with trying to be so particular with the heating/AC. Now I just pay the bill once a month. But if you are interested in keeping a close eye on things, the IAQ is the beast for you.
Just a sample of the performance log (there are also fault logs and alert logs). Anytime you can download from the IAQ to a stick and look at it on spreadsheet. Delta does show on the logs


----------



## dohat2 (Jan 29, 2021)

Folks - I am in the planning stages of doing something about my attic unit and one of the options is doing nothing. It is grossly oversized and I'm attaching some pictures. It's 2 ton coil and 100k 80% AFUE furnace and it serves the 2nd floor which is 650 sq feet. The outdoor condenser is 2 tons and was installed 3 years ago when I was stupid enough to trust my neighbor's reference hvac contractor. The furnace is perhaps 15 years old but working fine

Once the basement furnace is installed, I'll keep it at 70 degrees during winter and have traditionally kept the attic unit at 65 and it barely comes on except the coldest of days since heat rises up. We like it that way since it's quieter without hearing the hissing sound from the supply registers when sleeping. The problem is during summer season - it cycles every 15 mins and never removes humidity. I guess cold air doesn't rise up or we could have simply relied on the basement unit to cool the entire house and the 2nd floor unit would mostly serve just as a backup in case attic unit fails. Any other creative way for me to move air from 1st floor to 2nd floor during summer season?

Also, we have basic pink batt insulation in the attic today which is sort of in a bad condition. We plan to replace it with blown-in cellulose insulation and don't mind spending whatever is appropriate (still have to research all that and won't trust the local guys at all). Plus all our rim joists in the basement will get good insulation too. I wonder if these improvements will help the air somehow mixing and maintaining a somewhat constant temperature throughout the 1st and 2nd floor.. In the summer, we'd only be using AC when its 85+ outside which is usually 40 days max. If I set my 1st floor thermostat to 74, I don't mind if 2nd floor gives me 78 if at all possible and I'll still be comfortable while keeping my attic unit turned off

Thanks


----------



## beenthere (Oct 11, 2008)

Not sure that furnace has a blower that can be slowed down enough for a 2 ton A/C. If it can, it probably wasn't done when it was installed, and will cause high humidity in the summer because the coil can't get cold enough.


----------



## user_12345a (Nov 23, 2014)

beenthere said:


> The BOVA can be set to run at a lower capacity.
> 
> Standard single stage can't be set to run at a lower capacity.


I looked at the install manuals and spec sheet a while ago and saw nothing like that.
Just the ability to set the coil temperature, whether it can use an algorithm or not to vary it by 3f, and coil matchup.

Am I missing something and there's actually a way to limit this machine to say, 2 tons regardless of which indoor coil is used?


----------



## beenthere (Oct 11, 2008)

Setting the coil temp higher is how you set it for less capacity.


----------



## dohat2 (Jan 29, 2021)

Is it just a dip switch or something to set coil temperature higher? Also, do you think a properly insulated home will have air mixing in or very unlikely that 2nd floor will be comfortable with just the attic unit running in the summer? I don't even mind running the attic unit colder at maybe 68 degrees if it can reach that for the 8 hours of sleep at night

Thanks


----------



## user_12345a (Nov 23, 2014)

It looks like just drip switch - would be the accelerated heating/cooling that was enabled to get more heat out of the unit.

The higher coil temperature is listed at 47F, which is on the warmer side and dehumidification may be compromised. but perhaps the higher coil surface area relative to capacity may offset that.

They have published performance data for given air handler but don't say at what coil temperature.


----------



## beenthere (Oct 11, 2008)

The unit in the attic probably won't keep the first floor cool once it actually gets hot out.

Yes, just a dip switch setting.


----------



## dohat2 (Jan 29, 2021)

Folks - the hvac contractor is coming Monday to put in the 60k furnace. I do have a 110V outlet but the emergency disconnect switch which was 110 is now a 40amp 220V disconnect switch

Does anybody know if NYC/NYS code requires a disconnect switch or simply connecting to outlet should be fine?

Thanks


----------



## beenthere (Oct 11, 2008)

A. Very easy to convert that 220 back to a 120 volt line.

B. Not sure about NY, but in many areas, a plug is okay. As long as the receptacle is a dedicated recept.


----------



## dohat2 (Jan 29, 2021)

Guys apart from checking if the two stages of working correctly by adjusting thermostat a little and much higher, is there anything else I should verify about the install? I suspect the contractor may do a very quick job since he is not being paid anything additional for this labor so I want to be extra careful and checking and validating things

Thanks


----------



## beenthere (Oct 11, 2008)

He should do a combustion check in both stages.


----------



## dohat2 (Jan 29, 2021)

By combustion analysis, are you referring to checking the natural gas pressures, carbon monoxide in the flue gases, O2 levels, etc? Lot of things detailed here - what instrument is typically used to perform these tests and do most hvac installers do these checks?





__





Performing a Combustion Analysis


Safety of the appliance should be the primary goal of all technicians. The production of carbon monoxide (CO) in the flue gases should be kept below 100-ppm air-free, even though the allowable limit in the stack is 400-ppm air-free.




www.achrnews.com


----------



## beenthere (Oct 11, 2008)

The device is called a Combustion Analyzer.

A proper start up of a gas furnace should include incoming gas pressure, manifold pressure, combustion check, air temp rise across heat exchanger, and static pressure check to make sure the furnace is operating properly.

If your contractor checks manifold pressure, thats probably about all he'll check.


----------



## dohat2 (Jan 29, 2021)

with a bosch 60k furnace, what should the approximate temperature rise be?


----------



## beenthere (Oct 11, 2008)

The install manual list a min of 30° to a max of 60°F. So its best to set it up for a 45°F temp rise, 50° max with a clean new clean air filter. This allows for the air filter to get dirty and reduce air flow a little. Also helps to prevent condensation in the primary heat exchanger if you set the temp back to go a way for the weekend.


----------



## dohat2 (Jan 29, 2021)

Thanks. I am trying to buy a 16x25 filter but the manual states it should be high velocity of 600. Surprisingly the Amazon filters don't have any velocity specifications. Any idea what other online source is best for filters


----------



## beenthere (Oct 11, 2008)

A 16x25x???


----------



## dohat2 (Jan 29, 2021)

16x25 is what the manual specifies.


----------



## beenthere (Oct 11, 2008)

So I'll guess 1" thick. Almost any 1" thick will work. Just don't use 3M air filters, unless you are going to change it every 30 days faithfully.

Far better to have a 4" media filter cabinet installed, as they have a lower pressure drop. And allow better air flow.


----------



## dohat2 (Jan 29, 2021)

I still have the aprilaire 4210 that comes with merv 13 filters, would you recommend that


----------



## beenthere (Oct 11, 2008)

That will work. Might want to drop to MERV 10 filters though.


----------



## dohat2 (Jan 29, 2021)

strangely nothing less than merv 11 available for my aprilaire 4210 unit








Aprilaire Air Filters


Help keep your HVAC system running efficiently and smoothly with an Aprilaire Air Filter. Reduce maintenance time, cost, and upgrade performance over standard 1-inch filters with our patented self-seal technology that traps harmful airborne particulates. MERV 13 and MERV 16 filters were...




shop.aprilaire.com


----------



## beenthere (Oct 11, 2008)

Then use the 11. Still will have better air flow than a 13.


----------



## user_12345a (Nov 23, 2014)

dohat2 said:


> Guys apart from checking if the two stages of working correctly by adjusting thermostat a little and much higher, is there anything else I should verify about the install? I suspect the contractor may do a very quick job since he is not being paid anything additional for this labor so I want to be extra careful and checking and validating things
> 
> Thanks


Ask if the staging will be controlled by the thermostat or the furnace control board.
If it's by the board, it will fire on high after the end of the time delay and raising the setting won't bring high on.

Thermostat controlled staging is preferred, bring high on only when low is insufficient or the temperature is raised up.

---------------
To convert 240v circuit to 120v, just need to move one of the hots over to neutral.
If the breaker amperage is too high for the furnace (say they want a 15 amp maximum), I believe it can be switched out. This would be done to protect the wires in the furnace itself.


----------



## dohat2 (Jan 29, 2021)

Ok i have the honeywell 9320 thermostat and will make sure to tell him to have thermostat control the stating; thanks for the tip!


----------



## user_12345a (Nov 23, 2014)

dohat2 said:


> Ok i have the honeywell 9320 thermostat and will make sure to tell him to have thermostat control the stating; thanks for the tip!


Are you keeping the heatpump portion and getting a furnace and coil?
Many thermostats can not do dual fuel and stage the furnace.

It's possible to wire a heatpump as a straight cool - is that what you have in mind?
All heating done by the furnace?


----------



## dohat2 (Jan 29, 2021)

guys - i know some of the newer furnaces don't' allow thermostat to control staging so thought about checking the bosch manual. However in this manual I can't see a page which lists the dip switch that would allow my thermostat to control staging


https://www.bosch-climate.us/files/Bosch_96_Furnace_IOM_04.2019_US.pdf



Also the manual doesn't list anything for reverse staging. Do you think my furnace supports it or this is simply a thermostat function (I have Honeywell wifi 9320)


----------



## beenthere (Oct 11, 2008)

SW switch, S1 and S2 off.


----------



## dohat2 (Jan 29, 2021)

Thanks. Should I have him configure the heat pump for backup heat in case the furnace ever dies in the future?


----------



## user_12345a (Nov 23, 2014)

dohat2 said:


> Thanks. Should I have him configure the heat pump for backup heat in case the furnace ever dies in the future?


There are different ways to wire -> your thermostat does not support heatpump backed up by 2-stages of fossil fuel heat so you would lose thermostat furnace staging.


----------



## dohat2 (Jan 29, 2021)

I don't plan to use heat pump as primary. My primary will be stages of fossil fuel heat but wondering if I should use the heat pump as backup just in the remote case I ever lose natural gas or the furnace dies


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Thanks. Should I have him configure the heat pump for backup heat in case the furnace ever dies in the future?


No.

If the furnace should have a heating failure. Its easy to program it to use the heat pump.

There is no way to program it to automatically use the heat pump as emergency heat, or aux heat.


----------



## dohat2 (Jan 29, 2021)

They are starting the work; Thankfully I asked all questions here since he wasn't planning to keep a 12 inch difference between intake and exhaust vent but agreed to


----------



## dohat2 (Jan 29, 2021)

He didn't give me the model numbers over the phone but I just took pictures of the boxes that were delivered by the distributor. Seems correct and to what you had told me to have him install
BGH96M060B3A 96% 60K btu furnace
BMAC3036BNTD - 36K A-COIL


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> He didn't give me the model numbers over the phone but I just took pictures of the boxes that were delivered by the distributor. Seems correct and to what you had told me to have him install
> BGH96M060B3A 96% 60K btu furnace
> BMAC3036BNTD - 36K A-COIL


Yep, thats what you need.


----------



## dohat2 (Jan 29, 2021)

Is the attached image correct - exhaust is on the left? The installer said that in the manual it states the exhaust has to be pointed down and intake pointed up. He was surprised by that toi but said that's how he has to do it per the manual


----------



## beenthere (Oct 11, 2008)

Go to page 30 of the install manual. It shows the intake pointing down, and the exhaust pointing up, or or turned facing a way from the building.

None of the figures show the intake pointed up, and the exhaust pointed down.


----------



## beenthere (Oct 11, 2008)

Also look at page 31.

With the intake pointed up, your burner will be flooded with water when it rains.


----------



## beenthere (Oct 11, 2008)

The pipes are also too close to the walk. Unless you get no snow.


----------



## dohat2 (Jan 29, 2021)

Isn't figure 26 on page 30 which states Termination Confi guration - 2 Pipe Basement showing exhaust pointing up and intake pointing up and then out?


----------



## dohat2 (Jan 29, 2021)

This is the manual I'm reading - https://www.bosch-climate.us/files/Bosch_96_Furnace_IOM_04.2019_US.pdf


----------



## dohat2 (Jan 29, 2021)

Just to clarify the unit is being installed in the basement and the pvc pipes are coming out of the sidewall (not roof)


----------



## beenthere (Oct 11, 2008)

I missed that one. And its showing incorrectly.

Look at the pipes. It shows the one marked as exhaust, is actually running to the vent/exhaust of the furnace. And the one marked vent, running to the intake of the furnace.

Remove the top panel of your furnace, and you should see that the burner air intake is one the left side, and the exhaust is on the right side.

If he is still there, show that to him, so he can correct it. So your new furnace isn't ruined when it rains.


----------



## dohat2 (Jan 29, 2021)

Are you stating figure 25 I figure 26 being wrong in the manual?


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Just to clarify the unit is being installed in the basement and the pvc pipes are coming out of the sidewall (not roof)


Roof or sidewall. The intake is to be below the exhaust, and pointed down, and the exhaust pointed up, or to the side facing a way from the wall of the home.

I've installed lots of furnaces both in attics and basements. Its the same vent set up no matter which.


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Are you stating figure 25 I figure 26 being wrong in the manual?


25 and 26 are both labeled wrong.

Again Remove the top panel of the furnace. You'll see the intake is on the left. They just labeled the pipes wrong at the termination.


----------



## beenthere (Oct 11, 2008)

Look at figure 27. Both vents pointed outward, and both intakes pointed down.


----------



## dohat2 (Jan 29, 2021)

Figure 27 shows it correctly but it refers to 2 units in there but is still relevant. The HVAC installer left and didn't complete because he needs some extra parts to fully connect the gas. He didn't agree that there is a mistake in the manual and said you cannot follow the lines in the diagram but he's open to having us confirm with Bosch. Is bosch tech support pretty accessible when installers call them and do they get on the line in a few mins? That's the plan for tomorrow


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> Figure 27 shows it correctly but it refers to 2 units in there but is still relevant. The HVAC installer left and didn't complete because he needs some extra parts to fully connect the gas. He didn't agree that there is a mistake in the manual and said you cannot follow the lines in the diagram but he's open to having us confirm with Bosch. Is bosch tech support pretty accessible when installers call them and do they get on the line in a few mins? That's the plan for tomorrow


LOL.. In figure26 you can see the vertical method also. And it clearly shows which pipe is which.

Might be on hold depending if the call to tech support is made first thing, or later in the morning. They might even already know about the labeling mistake. They should be easy to talk to, they are use to all kinds of questions.


----------



## dohat2 (Jan 29, 2021)

beenthere - thanks for pointing this out; this goes to show that my constant paranoia on distrusting my local contractors and now even the manufacturers is valid. Me and my wife have looked through the diagrams for about 30 mins at this point and agree with you - I think the diagrams are drawn in such a way that you can actually follow the pipes. Just need to convince my installer and have bosch also talk to the installer and will post the results here


----------



## dohat2 (Jan 29, 2021)

quick side question - I already have 5 Merv 13 filters for the Aprilaire 4210 from before since I had bought an 8-pack at a discount on amazon Would this be too restrictive for the unit or should be fine?


----------



## user_12345a (Nov 23, 2014)

dohat2 said:


> quick side question - I already have 5 Merv 13 filters for the Aprilaire 4210 from before since I had bought an 8-pack at a discount on amazon Would this be too restrictive for the unit or should be fine?


60k furnace should do okay with merv 13 media filter.

The 1" high merv filters are the ones that should be avoided.

Just make sure the installer checks the temperature rise on both stages and adjusts fan speed if required. This needs to be done after verifying the gas pressure and fuel btu input are correct.
The install manual should have specific commissioning details.


----------



## beenthere (Oct 11, 2008)

Use them. Just keep an eye on them. Maybe check the filter every 90 days. 

If you listen closely to the blower motor when you put a new air filter in. You may pickup a higher noise as the filter gets dirty, which will be telling you its time to change it.


----------



## dohat2 (Jan 29, 2021)

From Bosch tech support early this morning - 
You are correct, the exhaust needs to be above the air intake. I will forward for a correction


----------



## dohat2 (Jan 29, 2021)

beenthere said:


> Use them. Just keep an eye on them. Maybe check the filter every 90 days.
> 
> If you listen closely to the blower motor when you put a new air filter in. You may pickup a higher noise as the filter gets dirty, which will be telling you its time to change it.


Thanks.


----------



## dohat2 (Jan 29, 2021)

Is it okay if the exhaust is pitched a little up going to the outside? My contractor thinks this will help with the condensate forming since any condensate can go back into the unit and the pipes will not freeze this way


----------



## dohat2 (Jan 29, 2021)

He said he doesn't do combustion tests for new installs but just a pressure test which came out at 3.5. He said he tested the 2 stages but didn't show me how but said it's configured for thermostat to manage. I guess I can open panel to make sure S1 and S2 are turned off. I measured supply/register at the unit and it's 108/62 for a 46 degree difference. Currently outdoors it's 57 with 30 humidity

Also my Aprilaire 700 humidifier isn't coming on even at the max level 7 but he said he heard it come on earlier. When putting in reset/test it does come on and I see water flowing fine. It's showing 34 RH on the aprilaire and I know these units can be pretty sensitive - I'll wait till it gets little less humid and see if it comes on - the manual states at level 7 it should be 45

Thx


----------



## dohat2 (Jan 29, 2021)

The exhaust is on the left and the intake is on the right. is there a chance rainwater gets into the intake and should I put another small PVC connector so it points down or not needed?

Thx
















Sent from my Pixel 4 using Tapatalk


----------



## dohat2 (Jan 29, 2021)

Here is a better picture of the intake









Sent from my Pixel 4 using Tapatalk


----------



## user_12345a (Nov 23, 2014)

dohat2 said:


> Is it okay if the exhaust is pitched a little up going to the outside? My contractor thinks this will help with the condensate forming since any condensate can go back into the unit and the pipes will not freeze this way


That's standard, it the exhaust pipe must slope towards the furnace.


----------



## dohat2 (Jan 29, 2021)

So it took about 3 hours for my unit to go from 58 to its target 72 but for the last 1 hour it's staying at 72 and not turning off. Is that normal? The outdoor temperature has stayed steady at about 58-60

Thx


----------



## dohat2 (Jan 29, 2021)

1) Am I paranoid about the intake not facing downwards? Could strong winds with rain allow water in and should I attach another down-spout part so it's facing downwards?
2) When it was 75 on heat mode, I changed thermostat to cool to test cooling function too. Oddly enough the heat pump came on but only for 2 mins and then I kept getting cool air from the supply registers but with the heat pump off. I monitored for about 5 mins - why and how would this occur? I thought the a-coil needs the heat pump operating to provide cool air
3) I can't find sw1 and sw2 which you said are required to be turned off for thermostat to manage staging. I can't find these on the board (I can only see sw3). Do you see it in the picture?

Thanks


----------



## user_12345a (Nov 23, 2014)

The thermostat wiring looks okay, though it's wise to have the t-stat set up to 2-stage cooling and Y2 connected.

There may be a link or dip switch to cut to enable the lower blower speed in cooling mode. If not, it may only run on low speed as wired without a jumper between Y1 and Y2.

On low cooling, the blower runs at a lower speed and the compressor slows down automatically in response.
Better for dehumidification and you get longer cooling cycles.

3 ton cooling is a lot for a 1500 sq ft space, best to have it run closer to 2 tons most of the time.



dohat2 said:


> So it took about 3 hours for my unit to go from 58 to its target 72 but for the last 1 hour it's staying at 72 and not turning off. Is that normal? The outdoor temperature has stayed steady at about 58-60
> 
> Thx


The air warms up, then the materials do, so after it reaches the setting, normal for the furnace to run a lot as the objects slowly warm up. Especially the 2-stage.

When the thermostat is controlling staging, it should drop back to low once it gets near the setpoint and run to maintain.

When you set it to cooling, the outdoor unit may have shut the fan to keep the pressure up in cool weather. I don't know if your unit is natively equipped for low ambient cooling.

Wait until warmer weather to test the cooling for real.


----------



## dohat2 (Jan 29, 2021)

You make a good point about low cooling and I'll evaluate how unit feels and performs in July and then start to make changes. I know the heat pump has a dip switch that can be adjusted to 2 tons but for some reason the engineer at Bosch said it's not recommended and didn't provide details. But I'll try it

I didn't I had 2-stage cooling with this unit too; I thought it was just a 2-stage furnace

Lastly I've only heard one stage so far with the movement of air - is stage 1 and stage 2 distinctly different with fan speed and would I notice?


----------



## dohat2 (Jan 29, 2021)

One thing I never understood is does the combustion fresh air intake somehow keep my house air cleaner as well i.e. does the fresh air coming into the furnace actually get circulated inside the house? That would be wonderful or 10 months of the year but really bad for me during 2 months of tree pollen season (april & may in nyc)


----------



## Missouri Bound (Apr 9, 2011)

dohat2 said:


> One thing I never understood is does the combustion fresh air intake somehow keep my house air cleaner as well


Nope. What it does is provide combustion air for the burner....that's it.
And that allows the furnace a supply of air that it doesn't have to draw from cracks, under doors, gaps in siding, etc.
With newer homes sealed so tightly it became necessary to allow the furnace to "breath".


----------



## user_12345a (Nov 23, 2014)

dohat2 said:


> You make a good point about low cooling and I'll evaluate how unit feels and performs in July and then start to make changes. I know the heat pump has a dip switch that can be adjusted to 2 tons but for some reason the engineer at Bosch said it's not recommended and didn't provide details. But I'll try it
> 
> I didn't I had 2-stage cooling with this unit too; I thought it was just a 2-stage furnace


You don't have 2-stage cooling, you have a variable capacity heatpump that adjusts the speed of the compressor to maintain a given coil temperature.

The dip switch impacts indoor coil temperature, which impacts capacity.
The colder the coil is relative to return air temperature, the more heat it absorbs.

Setting it to the higher temp (i believe 47F instead of 37) may reduce dehumidification.



The other way to adjust capacity is to adjust fan speed:

Slowing down the indoor fan reduces the amount of heat being absorbed, causing the coil to get colder -> the outdoor unit's controller detects this and reduces compressor speed until the target coil temperature is reached.

The fan in that furnace can be staged in cooling mode, which impacts operating capacity.

The combo of the return air temperature, indoor coil size, coil temperature setpoint and airflow determine what capacity it runs at.
It's a very unique heatpump and can only be as good as the person setting it up.



> Lastly I've only heard one stage so far with the movement of air - is stage 1 and stage 2 distinctly different with fan speed and would I notice?


You should notice a significant difference in airflow between low and high.

Go into the t-stat settings menu and make sure it's set up for 2-stages of heat with 1 stage of heating - conventional.


----------



## beenthere (Oct 11, 2008)

The S1 and S2 are at the top of the board about 2 or 3" to the right of the status light, and they are both on. And need to be sett to off for the thermostat to control staging.

The A/C is wired to the wrong terminal, it should be on Y/Y2, not Y1.

Check the wiring in the thermostat, and see which wire is connected to W, and to W2, he may also have reversed them at either the thermostat, or the board. Most people would use white for W1.

The intake and exhaust pipe are both to be slanted up hill as they travel away from the furnace. And the intake should be faced downward. To help prevent from getting rain in it.

If he doesn't do combustion test on new furnaces, he doesn't do them on older ones either, most likely. Good chance he doesn't even have a combustion analyzer. 

The continued cool air, could have come from the basement return, if it still has an opening for the basement.

At least the first 20 minutes of furnace run time were in first stage, so that would explain some of the 3 hours to raise temp14°F. 14° in 3 hours, is almost 5 degrees an hour, which is not bad. Again considering that 20 minutes o that was first stage.

The continued run after meeting set temp, may be the thermostat, as they round up temp, and tend to continue to run for some time, even though they display the set temp.


----------



## beenthere (Oct 11, 2008)

I also don't even see where the outdoor unit is wired into the system.


----------



## dohat2 (Jan 29, 2021)

I took a few more pictures and some of them may be redundant but they are taken from various different angles

























































































































Sent from my Pixel 4 using Tapatalk


----------



## dohat2 (Jan 29, 2021)

Due to my failure of being able to find honest people in the New York area I think I'm going to take it up on myself to learn everything well enough so I can maintain this equipment. Do you folks recommend any books? I found this one that does seem to cover the basics and maintenance








Audel HVAC Fundamentals, Volume 1: Heating Systems, Furnaces and Boilers: Brumbaugh, James E.: 9780764542060: Amazon.com: Books


Audel HVAC Fundamentals, Volume 1: Heating Systems, Furnaces and Boilers [Brumbaugh, James E.] on Amazon.com. *FREE* shipping on qualifying offers. Audel HVAC Fundamentals, Volume 1: Heating Systems, Furnaces and Boilers



www.amazon.com






Sent from my Pixel 4 using Tapatalk


----------



## Bob Sanders (Nov 10, 2013)

dohat2 said:


> Due to my failure of being able to find honest people in the New York area I think I'm going to take it up on myself to learn everything well enough so I can maintain this equipment. Do you folks recommend any books? I found this one that does seem to cover the basics and maintenance
> 
> 
> 
> ...


The aim is to understand A system, in detail not necessarily all systems in general.

Given that... better off studying YOUR system. Get out the wiring diagrams and the owners manuals and deduce what you need to learn based on what you don't understand in that literature.


----------



## user_12345a (Nov 23, 2014)

Ya I assumed the outdoor unit is wired in upstream of the board.

Thermostat wiring picture is barely visible, hard to make out.


----------



## dohat2 (Jan 29, 2021)

Does the outdoor unit wiring to the board look ok to you?

Also I saw stage 1 come on on thermostat for about 10 mins by itself to maintain 70 degrees indoor and it was *110 *at supply register. Then 20 mins later I did another test and raised to 74 and it shows stage 1 on for about 90 seconds and then stage 2 showed on too and 10 mins later, it was *126 *so looks like about 16 degree difference between stage 1 & 2. I thought it'll be a greater difference between the two stages

Below is the best pic I could get of the thermostat. Should I remove the black foam in the middle so you can see wires more clearly?


----------



## beenthere (Oct 11, 2008)

Are you sure it wasn't about minutes later that you rechecked air temp.

With the S1 and S2 switch set to bring on second stage after minutes, your thermostat is not controlling the staging.

It may be able to bring it on sooner. But the timer will always bring it on after minutes.


----------



## dohat2 (Jan 29, 2021)

In the test I did to set target temp to 74 (from 70, Stage 2 did come on within 90 seconds. Is my newer thermostat picture accurate? I'm wondering if I should pay the hvac guy what's pending or call him back
1) Like you said he doesn't seem to have a combustion analyzer
2) doesn't look like he wired everything per spec but did he reverse wiring in some way to the thermostat and again at the panel and that's how he got it to work without consideration to the right colors?
3) the temp differential between supply & return is about 58 which is high but I've not been able to find anything on the panel which lists out the required delta

Thx


----------



## beenthere (Oct 11, 2008)

The install manual will have allowable temp rise listed in it also.

Without seeing how all the thermostat wires are connected together, can't tell too much about wiring.

At thermostat, you seem to have 2 white wires. But at furnace, only 1 white wire.

In your test, did the furnace finish the heat call to 74 in second stage or first stage.


----------



## beenthere (Oct 11, 2008)

I believe your allowable temp rise is from 30 to 60 degrees.

So most likely, he didn't set up the blower speed correctly.


----------



## dohat2 (Jan 29, 2021)

It did get to 74 on stage two and for the last few minutes it came back to stage one and then stayed on again for a few minutes more before turning off. I think my temperature rise has been 58

Should I peel off the black material on the thermostat so I can take a better picture of the wires?

I wish Bosch would provide an audit service and send one of their engineers to make sure everything is wired correctly

Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> It did get to 74 on stage two and for the last few minutes it came back to stage one and then stayed on again for a few minutes more before turning off. I think my temperature rise has been 58
> 
> Should I peel off the black material on the thermostat so I can take a better picture of the wires?
> 
> ...


If a manufacturer sent one of their people to double check things. Furnaces, air conditioners, and heat pumps each, would cost 2 grand more.

The manufacturer only sends out a tech rep, when the contractor has exhausted all ideas from them from their phone conversations. 

No, its what wires are wired nutted together near the furnace that I am interested in.


----------



## dohat2 (Jan 29, 2021)

Okay I'll open up the panel on the furnace and try to take some zoomed in shots of the circuit board

Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

Look for wires connected out side of the furnace.


----------



## dohat2 (Jan 29, 2021)

The first picture is coming out of the humidifier and as the installer I'll explain it to me the thermostat controls the humidifier and the humidifier controls the furnace

the second and third pictures are the same but taken from a little different angle and I separated all the pairs so you can see the colors























Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

The humidifier doesn't actually control the furnace. It can start the blower, but not the heat.

I'll give him credit for using shielded cable. But can't give him much credit for the rest of the wiring. Other than, it seems to be working.
You will want, and need the blower speeded up, as with that high of a temp rise, your air filter will need changed every 30 to 45 days.


----------



## dohat2 (Jan 29, 2021)

So in layman's terms my furnace is talking too long to warm upp the house? Why will my filter get sorry soon? Another thing to consider is that there is some cold air coming from the basement rim joists which we discovered when we took the drywall out and we are going to patch it soon

Also I know you previously thought some of the wires are incorrectly connected? Is that still hold true or he has just used an uncommon method but the heating and cooling will still work?

Here is a video showing the wiring in more detail





Sent from my Pixel 4 using Tapatalk


----------



## dohat2 (Jan 29, 2021)

Can you tell me what page in the manual shows the recommended temperature rise. I am asking because he will not come back unless I prove it to him that something is configured wrong. As you can tell he has been frustrated with this job because he is making less money even though I think he knows that his application of an electric based heating system in an older home in New York City where we have extremely high rates was a real bad recommendation

Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

Wiring is probably okay. Its a bit of a rats nest. And without actually tracing out each wire. Can't say for 100% its okay. But looks like it might be.

Page 41 of the install manual.


----------



## dohat2 (Jan 29, 2021)

I am looking at the first line which is 60B3 which probably means 60k BTU which is what I have. I know it's good to be in the middle of the range 30-60 so right at 45 or max 50 like you said

I want to make sure I'm measuring correctly. I saw this post online - is that accurate? "The supply air temperature should be taken several feet away from the furnace so it isn't affected by radiant heat from the heat exchanger"

Hence, should I go to the supply duct that's closest to the unit and the place my thermometer 3 feet on top of the supply register which is on the wall? Same thing for the return register?

Thx


----------



## dohat2 (Jan 29, 2021)

I took these 2 audio files right outside the exhaust vent. Indoor was 70 and my target 74. The sound is occurring at least about twice every minute for 5-7 seconds and not sure if so much water is normal
password is pw








SENDEYO, Free image and photo host. Transfer and share PDF, ZIP, mp3, mp4 files


SENDEYO.Transfer of images and PDF files, ZIP, RAR, Audio, Videos ... Free image and photo hosting, CLOUD file hosting




sendeyo.com












SENDEYO, Free image and photo host. Transfer and share PDF, ZIP, mp3, mp4 files


SENDEYO.Transfer of images and PDF files, ZIP, RAR, Audio, Videos ... Free image and photo hosting, CLOUD file hosting




sendeyo.com





Temperature rise testing at noon with outdoor temp 62. I raised temperature from 70 to 74 to get both stage 1 & 2 on
Supply right at furnace inserting into an open area 115
Return at furnace and inserting thermometer in 72, 1ft away 69, 2ft away 67

Basement horizontal supply duct over ping pong table
1ft away in the path of the stream of air 109, 3 ft away 94, 3 ft away and one foot down 85

Living room supply by couch 110 (this supply duct is closest one to the unit on the 1st floor
Return with thermometer inserted in 76, 1ft away 76, 3ft away 76 (this is the only return on 1st floor)

Do these numbers look better to you? I don't know why they are a little different than my earlier testing but I took them quite meticulously. The temp rise does seems to be 35-45 which is where we want to be (I wonder if these better numbers are due to a pretty warm day today)

Thanks


----------



## beenthere (Oct 11, 2008)

Supply temp should be taken in the supply trunk 1 to 2 foot from the plenum, return temp should be taken at the furnace, either at the air filter, or 1 to 2 foot before it, with the humidifier bypass closed.


----------



## beenthere (Oct 11, 2008)

Check the slant on the condensate drain line coming out of the furnace. Sounds a little excessive for a warm day, but wouldn't be bad for a 40 45 day.


----------



## dohat2 (Jan 29, 2021)

I measured the pitch of both the PVC pipes going to the outside and also the picture the little water drain and everything seems to be between 1 to 2° angle. The only time the pitch is much higher is when the exhaust went goes outside in the last section of the video where it's a little dark








Streamable Video


Watch this video on Streamable.




streamable.com






Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

1.2° is 1/4" per foot rise.

I think some of the piping is more, and some is less.

The drain line for the furnace, may be a problem also. Doesn't look like the vinyl has enough slope at first.


----------



## dohat2 (Jan 29, 2021)

Can it be pitched going down as soon as it comes out of the furnace? It's 0 or maybe 0.2 degree nangle for those initial 3 inches as seen in the first picture. In the subsequent pictures you will see it has a better angle


----------



## beenthere (Oct 11, 2008)

Sorry, thats your A/C's drain. The furnace drain is the vinyl hose one on the left side of the furnace, connected to the black box.


----------



## beenthere (Oct 11, 2008)

Thats your A/C drain, which will probably work okay, since its a positive pressure in the coil area, and will tend to push the water.


----------



## dohat2 (Jan 29, 2021)

Is this the furnace drain? You are right there's not much of a pitch coming out of the furnace - I'm assuming there is no positive pressure from the furnace to push it out? I can try to simply bend it or maybe buy a pre-bent vinyl drain so it pitches better?


----------



## beenthere (Oct 11, 2008)

Yep, thats it.


----------



## dohat2 (Jan 29, 2021)

What do you think I should try first? maybe just try to bend it and hold that position for 5 minutes and see if it sticks?

Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

It won't stay in a new position by itself. At least not just from 5 or 10 minutes of being held.

Might try a string tied to something to hold it down a bit for a few days.

I don't use vinyl for furnace drains, I run PVC. SO can't tell you how long it might take until it will remain down better.


----------



## dohat2 (Jan 29, 2021)

So I did some testing with a $50 AP-866A anemometer that I can use as a reference for future if I change fan speeds, etc. if it's not considered the most accurate and I simply held the device on the supply/return ducts and moved it around a little to get the highest reading each time

Supply register in basement closest to the unit (about 15ft away) - 

1105 with stage 1 only
1181 with stage 1 & 2 on
1050 with just air blower on (humidifier)
Return register on 1st floor - 580cfm

I also measured the bathroom exhaust fan and got a 470cfm reading but it's only rated for 80cfm so I suppose there is another formula to get actual cfm - doesn't sound like I'm doing this correctly

Thanks


----------



## beenthere (Oct 11, 2008)

An anemometer reads air velocity/speed of air movement, not the CFM. 

You make six reading of air velocity across the register, average them out. Then convert the free opening of the register to sq ft. Then divide the sq ft free area into the averaged velocity.


----------



## dohat2 (Jan 29, 2021)

This video shows how the duct is run - 




Measurement taken at supply duct which is roughly 18ft from plenum and tried to get the max velocity which is 14mph. I removed the grille and the rectangular duct is 7 high and 12 wide. I'm getting 718cfm - does that sound correct? I thought 1150cfm is what this unit is spec'd for but perhaps that's a measurement that has to be taken right at the unit

I used this site to do the calculations - https://www.engineering.com/calculators/airflow.htm


----------



## beenthere (Oct 11, 2008)

You would need to make several measurements across the rectangular duct, and then average them together, to check the CM of the main trunk line. Usually, a trunk line would be checked using a pitot tube.

With the register off. Check the velocity of the opening with the meter against the duct, and facing toward you. Take size measurements, over lapping where the head ended. Average those readings. Then convert to CFM.

A 7x12 moving 718 CFM, would be at a static 2.6".


----------



## dohat2 (Jan 29, 2021)

I don't understand this statement - take size measurements, over lapping where the head ended 

Do you think I could DIY myself here to calculate what the static pressure of my system is without hiring a professional? Basically I'm trying to identify if my duct work is really bad and if it is, I'd like to make changes to the duct work because I want to avoid premature equipment failure

I took average measurements and get a 13.1 mph measurement which gives me 672cfm. I do understand what is static pressure but not sure how to express cfm in terms of static like you do above. Does 672cfm look alright to you for a measurement taken 18ft from the plenum?

Thanks


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> I don't understand this statement - take size measurements, over lapping where the head ended
> 
> Do you think I could DIY myself here to calculate what the static pressure of my system is without hiring a professional? Basically I'm trying to identify if my duct work is really bad and if it is, I'd like to make changes to the duct work because I want to avoid premature equipment failure
> 
> ...


That anemometer isn't made to be used in your duct system. Although 600 CFM give or take a bit would be okay.

Static is easy to take. Nice to have a A-303 static probe to do it.

It then gets placed between the evap coil and the furnace. Or, the furnace's high limit removed, and the static probe stuck in the hole, and the hole taped over, or covered some other way. And that is your supplt static.

Then a hole drilled into the return panel, or air filter panel, and the probe put between the filter and blower compartment. That id your return static. Then the numbers added together ignoring the negative sign on the return static. That is your TESP, Total External Static Pressure.


----------



## dohat2 (Jan 29, 2021)

Thanks got it. One more thing - on my aprilaire humidifier 700, there is a certain behavior which I'm not sure if it's normal or not. It occurs when there is no heating on. The unit comes on for a few seconds and turns off. Basically it shows 50% RH and then starts dropping by itself to about 39 when it comes on. As soon as it comes on, it again rises to 45 and then turns off. You can see the whole video or simply skip to 1:16. I know the air blower is not coming on since I hand my hand on it and didn't' feel it come on







Thanks


----------



## beenthere (Oct 11, 2008)

Need the furnace blower to come on also. May be another thing your installer has wired wrong.


----------



## dohat2 (Jan 29, 2021)

It does come on and quite often I do notice my air blower turned on and blowing room temperature air for 30-40 mins straight because the humidifier has instructed it to. But at these routine checks it does not seem to come on. I will look at the humidifier wiring diagram and try to make sense of it

Sent from my Pixel 4 using Tapatalk


----------



## dohat2 (Jan 29, 2021)

I've been looking at rodent and insect screens. Is it recommended to install these and have you seen instances where warps develop nests inside the pvc pipes or even in the furnace? This company gave me some scary stories although they may be biased since they want to sell me this - they said I should switch from the 90% airflow rodent screen in the winter to the 70% airflow bug screen in the spring. I would like to simply install the rodent screen and have one less thing to remember unless you think warps, insects often do damage









PVC Vent Screen for Insects and Rodents Model PVS-IS2


Our PVS-IS2 PVC vent screen offers superior protection for 2" high efficiency furnaces, power vent hot water heaters and boiler vents. This screen guards against insects and rodents.




pvcventscreens.com












PVS-RS2 PVC Rodent Vent Screen


Our PVS-RS2 PVC rodent vent screen will protect your high efficiency furnace, power vent hot water heater or boiler from unwanted animals such as squirrels and birds.




pvcventscreens.com


----------



## beenthere (Oct 11, 2008)

Seen a few times that wasp have made nest. Problem with the screen on the exhaust is that it tends to freeze up, and cause no heat.

I don't put screens on the intake or exhaust.


----------



## dohat2 (Jan 29, 2021)

Guys - if there is one device I should have in my home to measure cfm, would it be the $50 anemometer or something else? I have a 2nd floor project too and always interested to measure how much cfm I'm getting out of each duct and look for improvements. I'm still in the return window so can exchange for another device but hoping to be under $100

Thanks


----------



## beenthere (Oct 11, 2008)

A manometer is used to measure the static pressure the blower is working against, and then the install manual is checked to see how much air the furnace/air handler is moving.

An anemometer is used at the registers to see how much air is coming out of them. This MUST be a series of readings across the register, and then average out. And then the velocity is compared to the chart for that register.


----------



## dohat2 (Jan 29, 2021)

I'm trying to get a new HVAC duct into my kitchen extension area which is usually 7 degrees cooler than the rest of the home because of no duct + 6 windows and a rear door. The entry to the kitchen does have a circular duct but it's got far lower cfm than other ducts and the pics below show it's squeezed into the ceiling of the basement. I don't exactly know how the circular duct is run but obviously it's a cut out from the main rectangular duct somewhere in the ceiling and I'll investigate that when I open the ceiling

The last pic is what I propose. You will see the main rectangular duct for which I posted velocity readings already and this trunk currently supplies to the basement register and also then makes a right turn to two registers in the 1st floor office. I want to make a cut and go left and then north to the kitchen above. The duct will be literally 6 inches from the rear wall of the house but as you know, I do plan to use blown-in insulation on the rim joists of the basement and seal everything up very well. I do understand doing this will reduce airflow to office and to the basement but those areas are a little warmer anyways currently so I'm fine with reducing resultant airflow by 30% to these areas

While I'm at this and see how the current kitchen circular duct connects while opening parts of the ceiling, I may just remove it all together and connect to this same rectangular duct for better performance

Thanks


----------



## beenthere (Oct 11, 2008)

A 4x6 duct, is around 70 CM. So also connecting the other duct to it, will get you less air to the kitchen.


----------



## dohat2 (Jan 29, 2021)

Ouch didn't realize. What do you advise we do here? I'm a tall guy so can't go more than 4 inch depth since it will touch my head but I can go broader like 10x4 if needed. Or we can simply create a brand new rectangular trunk from the furnace and run it parallel to the current trunk and maintain same dimensions too but it'll obviously be more work. I'm guessing this will similarly affect airflow of the other rooms too. Btw, how many main trunks can one connect from a furnace? We have 1 rectangular & 2 circular today

Thanks


----------



## beenthere (Oct 11, 2008)

Leave the current pinched run alone. And add the one you said, but as a 10x4. Should get you over 100 CFM more to the kitchen.


----------



## dohat2 (Jan 29, 2021)

beenthere said:


> Leave the current pinched run alone. And add the one you said, but as a 10x4. Should get you over 100 CFM more to the kitchen.


So am I running the 10x4 direct from the furnace or an off-shoot from the current trunk? Thanks

Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

Direct from furnace would probably work better.


----------



## dohat2 (Jan 29, 2021)

guys - I noticed the heat was on but the temperature wasn't rising on this really cold April day here (35 degrees). I went down and saw 8 red flashes from my furnace and the manual lists a whole list of causes. Given the furnace has been in place for literally just a few weeks, what could be the most probably cause of this

I was on vacation for a few days and had set the temp to 50. This morning I set the target to 69 and it did get to 63 before this error occurred in about 8 hours

Thanks


----------



## beenthere (Oct 11, 2008)

What error code is 8.


----------



## dohat2 (Jan 29, 2021)

Here's a screenshot from the manual










Video of 8 flashes - Streamable Video

Thermostat indicates following schedule in recovery


----------



## beenthere (Oct 11, 2008)

Check the exhaust and intake pipe terminations for ice build up.


----------



## dohat2 (Jan 29, 2021)

beenthere said:


> Check the exhaust and intake pipe terminations for ice build up.


I checked them both out and they are just a little wet to the touch but no ice at all as far as my fingers could go which is about 3-4 inches

Sent from my Pixel 4 using Tapatalk


----------



## dohat2 (Jan 29, 2021)

After a one hour timeout the heat started by itself. I had read on another article that the furnace does this when the gas valve is dirty or has incorrect pressure


----------



## dohat2 (Jan 29, 2021)

The heat at the supply register is very variable and sometimes I'm only getting 73 and then for a few minutes I may get 90. On the thermostat it shows both stage 1 and stage 2 are on


----------



## dohat2 (Jan 29, 2021)

8:15am - power cycled the unit at the disconnect switch
8:25am - at peak, temp at supply register was 121
8:26am - temp started dropping
8:30am - settled at 82
8:36am - dropped to 72 and heat stopped even though thermostat showed heat on and stage 1 & 2 on
8:47am - no change in status and now furnace showing 8 red flashes. I suspect furnace will wait an hour before coming back on


----------



## beenthere (Oct 11, 2008)

Its a soft lockout. So it restarts after an hour.

Looks like your having a gas supply problem to the furnace.


----------



## dohat2 (Jan 29, 2021)

Should I call the HVAC guy back again or a plumber? I have the same gas supply to the range and also the hot water heater and they are all working fine. If it were you, where exactly would you start to troubleshoot this?


----------



## beenthere (Oct 11, 2008)

I'd connect my manometer to the inlet side of the gas valve and watch what it does as the furnace operates. And watch what the furnace was doing. Based on what I did or didn't see. I'd check the manifold side of the gas valve. And proceed from there.


----------



## beenthere (Oct 11, 2008)

Best to call the installer first.


----------



## dohat2 (Jan 29, 2021)

Ok, contractor just got here. He said gas pressure is right, he just measured and it's 3.5. However, he sees water collecting in diffuser fan. He is clearing it out and going to give the exhaust vent a greater pitch so it's easier to go out. He thinks the constant gurgling is occurring due to this and because the unit is collecting water, it's instructing the gas valve to turn off


----------



## dohat2 (Jan 29, 2021)

Attaching pictures here and you can see some water on the floor too























Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

3.5" is not always the right pressure. That is why a combustion analyzer is suppose to be used. Also, what is the gas pressure in first stage.

What is the temp rise in both stages.

The exhaust pipe is suppose to pitch back toward the furnace. which means the water is suppose to run back toward the inducer.

Good chance, there is a drain issue.


----------



## dohat2 (Jan 29, 2021)

He doesn't have a combustion analyzer. He said gas pressure is 3.5 consistently and after changing the pitch (each pvc connection which is 5 total small pvc pipes) pitches down to the unit by at least 5-10 degrees now. It was 68 indoors and we raised it to 74 to test and all through the 30 mins of testing before it got too warm, I didn't hear the gurgle at all. Also, on the drain pipe the water seems to drain much faster now and before, it seemed to be a little hesitant in its movement. He said there was some negative pressure building up and he has corrected that. I hope this fixes it but if not, there is a 1 year warranty on the install so I have until March 2022

Thanks


----------



## dohat2 (Jan 29, 2021)

stage 1 temp rise is 45 and stage 2 temp rise is 54 - he didn't care about those numbers unfortunately. I know you said it' should be a max of 50


----------



## user_12345a (Nov 23, 2014)

If you get the average btu/cu ft heating value for your area/provider, you can clock the gas meter with all other appliances off and determine if the input close enough to what's on the rating plate and not over.

The reality is that the natural gas btu content varies slightly during the year, the vent length varies on the install, the density of the air varies which all impact combustion.
It's not an exact science.
So I would not wouldn't worry about having it fine tuned with analyzer provided the volume of gas/ flow rate is where it should be. *This is all the manufacturers say is necessary. Some makes seem to give a range of 3.2 to 3.8" and others just say 3.5" -> major adjustments made by changing orifices if manufacturer approved, not by pressure.*
The orifices it came with are probably for 1000 to 1050 btu/cu ft gas which should be close enough in most of the continent.
Though it's a good idea to at least check exhaust monoxide to make sure it's running safely.

If the temperature rise on high is above the max rise on the nameplate, the high heat fan speed should be increased.

This is only my opinion and beenthere knows far more.


----------



## beenthere (Oct 11, 2008)

dohat2 said:


> stage 1 temp rise is 45 and stage 2 temp rise is 54 - he didn't care about those numbers unfortunately. I know you said it' should be a max of 50


He didn't care that temp rise is higher than the manufacturer said it should be. Hmmm, hope he doesn't install many furnaces.

3.5" may or may not be good for your area. Did he even bother to check the pressure in first stage.


----------



## beenthere (Oct 11, 2008)

Remember, the exhaust and intake pipe should both rise a min of 1/4" per foot as they run outside. 

So did it have that rise when he first installed it, or not?


----------



## dohat2 (Jan 29, 2021)

The rise on the exhaust didn't have 1/4 per foot at the beginning and was completely level for 1.5 feet. Now, each foot at least has 1/2 rise but perhaps more

The intake vent doesn't have much rise at the beginning currently but then has a 1/4 rise - is that going to cause an issue? Why is the rise needed for the intake? 70% of the pvc pipe does have the 1/4 rise but not the beginning

user_12345a - thanks for your inputs too; I'll try to get these values


----------



## beenthere (Oct 11, 2008)

The intake can get water in it when it rains.


----------



## dohat2 (Jan 29, 2021)

I checked out the intake when there is heavy rainfall and fortunately it is 2 ft away from the chimney protrusion. Hence I did not see any water going in. I saw one or two drops fall under at the bottom of the pvc pipe entrance but the mesh cover I installed keeps those drops from getting in. I am going to test this out through the heavy rainfalls in April and May. If I open the furnace covered and look at the inducer I should not be seeing any water and it should be completely dry over there correct?

Please keep in mind I agree with everything you say but obviously my contractor waits for things to break before agreeing to fix them. Our relationship isnt good and he doesn't admits any mistakes but keeps cribbing that this was not a profitable project for him. At least he is coming back to perform the fixes because in this New York area a lot of people just don't come back once they have your money

Sent from my Pixel 4 using Tapatalk


----------



## dohat2 (Jan 29, 2021)

It rained quite a bit today. Should I open the furnace panel and look at the inducer to see if there are any signs of water or should it be completely dry?

Sent from my Pixel 4 using Tapatalk


----------



## beenthere (Oct 11, 2008)

Not if the heat didn't run.


----------



## dohat2 (Jan 29, 2021)

Hi there - I just realized there is a lot of air leaking where I show the red mark as well as all other 3 sides. Should I be using hvac tape to seal it?







air


----------



## beenthere (Oct 11, 2008)

Yeah, silver foil tape will seal it.


----------

