# Is charging a R410a system the same as a R-22 system...



## beenthere (Oct 11, 2008)

Charged by superheat and subcool.


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## paulie pizza (Mar 17, 2009)

thanks..
I bought a fieldpiece subcooling and superheat meter........I have not used it yet.....im going to read up on the instructions and go that route on charging by superheat and subcooling........can you charge a system when it is cold out?......On r-22 you can wrap the condensor with a tarp and clear the sightglass to fool the unit....is that a good way to do it and if it is, would that work for 410a......and does this make sense to you ?


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## yuri (Nov 29, 2008)

If life were only that simple. I use the charts that give you superheat and subcooling and (Lennox, approach) methods and are included with the unit. You have a lot to learn but we will try and help you if you have a bit of thick skin. You have to understand the type of load (heat, humidity) airflows and how they affect a unit. A lot of different conditions can affect charging a unit an fool you into overcharging etc. A dirty A coil will slow down the air/lower suction pressure etc so I would recommend you do the NATE courses and learn about all this. I will rarely charge a unit when it is less than 70 deg F outside AND you need a load in the house. Wrapping the condensor rarely is accurate and unless you have LOTS of experience it will go badly for you and generate lots of callbacks. Lennox has lots of internal training courses for their dealers and if you deal a major brand then check with them if they have one for you. Make sure you understand all the dangers of working with high pressure refrigerants. Safety glasses, gloves, NO damaged or dubious quality hoses.:yes:

Good Luck


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## beenthere (Oct 11, 2008)

Using a tarp and clearing the sight glass isn't a great way to charge in cold climate conditions.

A tent, or tarp is find.
but, you need to have the subcool for those outdoor temp conditions you are simulating.

If its a piston/fixed metering system. then you need to simulate a warm/hot out door day, that matched the indoor conditions.

Simulating a 95° outdoor temp, with a 50° indoor wetbulb, won't get your charge correct.

With that indoor condition, a 60° outdoor temp would be what you would simulate.


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## kenmac (Feb 26, 2009)

I would also get a set of low loss fittings for your guage hoses..don't use the same hoses / fittings with R410 & then try to use them on R22... Make sure your hoses are rated for the pressures of R410


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## paulie pizza (Mar 17, 2009)

Thanks for help Beenthere and Yuri......
_I bought a 410a book today and going to read up on it....I'm going to take the class next month. I want to be ahead of the class I have installed units in the winters(410A)....brand new systems...all 9 yards...ducts,piping and etc.... installed a sight glass and drier. I measured the pipng to the exact or closest feet of Refrigeration lines....leak checked, pulled a vacum on system and weighed in correct ammount of 410a for the length of pipe run...I've put in about 10 systems over the winter and as the weather starts to get warm, I will be ready to check theses systems for proper operation......_
_thanks all for your time_
_Paulie Pizza_


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## biggles (Jan 1, 2008)

with the unit not powered up....and the VAC completed go right to the king valve on the condenser with a single hose and the 30lb drum of freon.connect the hose to the upright tank crack the tank to bleed a slight gas pressure and hook it up to the king valve and open it half way.open the tank valve 100% and flip the tank......liquid will fill the LL into the air handler and the bottom of the condenser till the pressures equalize.you are now 80-90% charged without even running the compressor:whistling2:.shut the freon tank off all the way up on the king valve stem to full open running position disconnect the single hose.the rest if any of the charge will be determined by the SH/SC readings with some what of a load on the evap coil...check your amps on the runnibf compressor inlet air into the condenser pus 30F to see how the head is wit the days temperatures.then fine tune it with those readings..forget the sight glass being clear:huh:if you have a laser thermometer hit the bottom bends on the condenser working your way up the rise in temp will be the difference between the liquid and the hot gas.2 to 3 rows on the bottom for liquid.


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## hvaclover (Oct 2, 2008)

paulie pizza said:


> Thanks for help Beenthere and Yuri......
> _I bought a 410a book today and going to read up on it....I'm going to take the class next month. I want to be ahead of the class I have installed units in the winters(410A)....brand new systems...all 9 yards...ducts,piping and etc.... installed a sight glass and drier. I measured the pipng to the exact or closest feet of Refrigeration lines....leak checked, pulled a vacum on system and weighed in correct ammount of 410a for the length of pipe run...I've put in about 10 systems over the winter and as the weather starts to get warm, I will be ready to check theses systems for proper operation......_
> _thanks all for your time_
> _Paulie Pizza_



I'm gonna have to talk to my Godfather. If 'da pizza guzys is gonna cross into our territory wez is gonna do 'da same. How do you guys like your pie?

Hey Beenthere, by pass the slef cleaning lock on the kitchen stove. We got pizza to make:laughing::jester:


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## beenthere (Oct 11, 2008)

hvaclover said:


> I'm gonna have to talk to my Godfather. If 'da pizza guzys is gonna cross into our territory wez is gonna do 'da same. How do you guys like your pie?
> 
> Hey Beenthere, by pass the slef cleaning lock on the kitchen stove. We got pizza to make:laughing::jester:


LOL...

Acouple years ago, I could have got you 2 of Dominos old electric pizza ovens.

POS from day one.


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## hvaclover (Oct 2, 2008)

Dominos is headquartered here.

Pizza sucks. We have a large local chain franchise called Jets. Cheap price but taste great!

Just had some an hour ago and my mouth is watering thinking of it.


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## beenthere (Oct 11, 2008)

There is only one place around here that makes good pizza.

And its not D's or PH.


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## hvaclover (Oct 2, 2008)

beenthere said:


> There is only one place around here that makes good pizza.
> 
> And its not D's or PH.



Bet it's run by a mom and pop operation. They care about the quality of their food more than the bottom line.


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## beenthere (Oct 11, 2008)

But an expensive mom and pop.

Actually, just pop.


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## hvaclover (Oct 2, 2008)

Pizza and a good beer..those were the days:yes:


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## dbmarsbrit (Mar 19, 2009)

paulie pizza said:


> is charging a 410a the same as Charging a R-22 system......other than charging a 410a in a liquid form


yes other than pressure difference between 22 & 410a
remember 410a is a blend 
it must be added as a liquid 
i,m an hvac-r service tech


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## paulie pizza (Mar 17, 2009)

dbmarsbrit said:


> yes other than pressure difference between 22 & 410a
> remember 410a is a blend
> it must be added as a liquid
> i,m an hvac-r service tech


 Thanks dbmarsbrit,
As I keep reading up on 410a.....weighing in the charge in a liquid form and pressure's are higher than 22.....I still put a sight glass,drier and deep vacum on system before I put in additional charge needed. I have a chart on ammount needed for total run of pipng..... and it works great

Lately we have been installing drier as close to A/H to catch anything just before TXV......does that make a difference to install in attic or by the condensing unit...other than the drier getting hot in attic...I have taken old units out with drier in attic.....


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## hvaclover (Oct 2, 2008)

paulie pizza said:


> Thanks dbmarsbrit,
> As I keep reading up on 410a.....weighing in the charge in a liquid form and pressure's are higher than 22.....I still put a sight glass,drier and deep vacum on system before I put in additional charge needed. I have a chart on ammount needed for total run of pipng..... and it works great
> 
> Lately we have been installing drier as close to A/H to catch anything just before TXV......does that make a difference to install in attic or by the condensing unit...other than the drier getting hot in attic...I have taken old units out with drier in attic.....


Can't use a sight glass on a zeotrope refrigerant to check charge. Can have bubbles cause of the slight temp glide characteristics of the refrigerant.


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## beenthere (Oct 11, 2008)

Except for systems that had a receiver. Sight glasses were never a good way to determine if the system was charged properly.


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## dbmarsbrit (Mar 19, 2009)

paulie pizza said:


> Thanks dbmarsbrit,
> As I keep reading up on 410a.....weighing in the charge in a liquid form and pressure's are higher than 22.....I still put a sight glass,drier and deep vacum on system before I put in additional charge needed. I have a chart on ammount needed for total run of pipng..... and it works great
> 
> Lately we have been installing drier as close to A/H to catch anything just before TXV......does that make a difference to install in attic or by the condensing unit...other than the drier getting hot in attic...I have taken old units out with drier in attic.....


 the only difference is you may not catch any contaminants in the linset 
between the drier and the a/h txv
I haven't seen a txv system that doesn't have some sort of internal
screen/filter adding a liq. line drier at the or as close as possible
to the txv is prefered hot attics are not really an issue
on large commercial units suc.&liq. filter driers are often open to the elements/sun


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## dbmarsbrit (Mar 19, 2009)

beenthere said:


> Except for systems that had a receiver. Sight glasses were never a good way to determine if the system was charged properly.


 could you explain this to me


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## beenthere (Oct 11, 2008)

A sight glass only shows that you have, or don't have a solid head of liquid at IT.

A sight glass installed near the TXV is better then one at the condenser.

But, a kink in the liquid line, will show vapor, and most techs just add charge until its full, over charging the system.

One mounted at the condenser will show solid liquid, and then the system is under charged. And many techs can't figure out why it won't cool with a full head of liquid. And then they say it must be a bad compressor..

A dirty condenser, can be over charged enough to show a full sight glass.

Without checking sub cooling. Its easy not notice that its over charged. No matter what location the sight glass is installed at.

Charging to a full sight glass can make the compressor work harder to start, and to run. Because its over charged.

Systems with liquid receivers, won't have a good sub cooling readings after the receiver.

SC has to be taken before it.

But, even with proper SC, you may have to add more to get a head of liquid from the receiver(The receiver is at saturation).

A combination of the sub cooling reading before the receiver, and checking if the sight glass is showing a full head of liquid is a best practice.


When sight glasses are used as the only means to determine if a system is charge correctly or not.
They aren't charged correctly.


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## imastar4nascar (Jun 22, 2009)

*Site Glasses*



beenthere said:


> A sight glass only shows that you have, or don't have a solid head of liquid at IT.
> 
> A sight glass installed near the TXV is better then one at the condenser.
> 
> ...


today, sight glasses are only good for moisture indications. the old days of charging until it's full is a fools way of charging. package rooftops you weigh in the charge, split systems use a chart.


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## beenthere (Oct 11, 2008)

Sight glasses were never a good way of charging a system(A/C, or HP, refrigeration can be different).

Even though atleast one A/C manufacturer had instructions to charge by sight glass.


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## beenthere (Oct 11, 2008)

The real shame.
Is that with all the improvements with test instruments. Including the cost of them.
Techs still want ot use a sight glass.


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## imastar4nascar (Jun 22, 2009)

*It's a shame*

I graduated in 1995 with an associates degree in HVAC. I have been fighting the old school tech philosophies ever since. I still have techs who charge by pressures, then wonder why they get stuck doing pm's.

with the money i pay techs it's a shame they don't want to buy the instruments that let them do their jobs well.


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## beenthere (Oct 11, 2008)

I use to be a SM for a company.

Use to get radio calls from techs. Asking me whats wrong, why can't they get teh system to cool right.
When I would ask them what the SH and SC was. They would say something like.

I forget the exact numbers, bu they were both good.
So I'd tell them to radio me back when they took those readings again. And then tell me what they are.

A far number of times. They wouldn't call back. And the next day, when I looked at the ticket. And saw they changed out a LLFD, or Cleaned the coil, and then it worked right again.
I'd ask them how the SH and SC could have been ok the first time.

Then just mumble.

Sometimes when they have the instruments, they still don't use them.

And what I never understood. Was since they were paid by the hour. Why not take the few minutes required to take all the readings. And find the real problem faster.


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## imastar4nascar (Jun 22, 2009)

*Omg*

you lived it right there. Why didn't you put in a work description? "because i was running behind" get paid by the hour doesn't mean they do what they are told lol.


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## hvaclover (Oct 2, 2008)

beenthere said:


> I use to be a SM for a company.
> 
> Use to get radio calls from techs. Asking me whats wrong, why can't they get teh system to cool right.
> When I would ask them what the SH and SC was. They would say something like.
> ...



Radios? You were lucky Been. We used two cans with a string connected.


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## beenthere (Oct 11, 2008)

hvaclover said:


> Radios? You were lucky Been. We used two cans with a string connected.


LOL...

When I first started.

We used cans too. We just didn't have the string for the cans. :laughing:


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## imastar4nascar (Jun 22, 2009)

*Your telling me*

I started with radio, progressed to nextel, and now i'm on a palm treo. We don't use paper at all!! That is what makes me laugh so hard when these techs tell me they don't have the time, but if you short them 5 minutes on their pay they know exactly where they were shorted!! I'm so over it already.


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## DanDattomo (Jun 30, 2009)

*410a Charging*

Yuri:

How does one become a Lennox Dealer and take advantage of the training??

Thanks.

Dan


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