# Furnace venting out side of house / advice (pic attached)



## nutshellml (Dec 14, 2015)

Afternoon, I recently had my furnance relocated to the other side of the basement. The vent was piped out the side of the wall (see attached). What I envisioned prior was a vent cap similar to what my direct vent fireplace has, something more flush to the house. This is a little more obtrusive than I thought and will be difficult to cover with shrubbery. Any input/advice or recommendations that would pass general code?


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## user_12345a (Nov 23, 2014)

Does this unit have an accessory that allows for sidewall venting?

'cause usually the draft inducer in a mid efficiency furnace is not designed to "push" exhaust out, just produce a negative pressure in the heat exchanger.

The exhaust from mid efficiency furnaces rises by gravity.

The way it's vented looks dangerous; the exhaust is 300 to 400F+ degrees, anyone who touches that pipe could get third degree burns. It's at ground level. Now, it could be double wall so the outside may not be burning hot. Still not great.



proper way to go would be installing a condensing furnace.


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## nutshellml (Dec 14, 2015)

It's a double wall or b vent I believe it's called. My furnace is a Lennox not high efficiency, circa 2013/2014.


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## user_12345a (Nov 23, 2014)

Is there anything at the furnace (like a second venter motor on top) which permits this venting?


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## nutshellml (Dec 14, 2015)

I have to check, but believe it's the SL line and definitely variable speed.


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## roughneck (Nov 28, 2014)

Is this an 80% or 90%+ furnace? 
That's not right either way. Distance to combustibles, draft, all kinds of stuff done wrong there.


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## roughneck (Nov 28, 2014)

Take a picture of the furnace


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## user_12345a (Nov 23, 2014)

nutshellml said:


> I have to check, but believe it's the SL line and definitely variable speed.


Does that metal pipe connect directly to the furnace?

or is there a second power venter?

a mid efficiency furnace simply can not be vented like that on it's down. 

was this job inspected?


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## yuri (Nov 29, 2008)

Looks totally illegal and bush league to me. You WILL get birds nesting inside it like that.

It should have a termination kit like a fireplace.

Call the gas company or whoever does your gas inspections and have them look at it as local codes can be different that national ones.

We don't sidewall vent our furnaces but Lennox should have a approved kit for it and their dealers can get it.


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## nutshellml (Dec 14, 2015)

Ok thanks, I'll check my my contractor and ask about Lenox wall termination kit. Good point about nesting. Def don't want that. I would assume that my contractor checked w Lennox to make sure it could be vented out the side, just need to make it pretty and safe!


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## yuri (Nov 29, 2008)

That looks totally illegal and is prone to vandalism. Kids can turn that elbow up and rain will get in. No way that meets the code.

I had a contractor do a house reno and had to extend the PVC venting on a high efficiency furnace. He just grabbed a stock aftermarket concentric kit from a Carrier dealer that we use on lots of them plus Ducanes etc and slapped it on. Caused a whole bunch of pressure switch tripping problems etc. I had to get him to buy the proper low pressure drop Lennox version and install it and then it was OK.

Point being I doubt these guys even check with Lennox and this dude just slapped it out like that.


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## user_12345a (Nov 23, 2014)

never assume that any contractor is competent.

take pictures of the venting inside starting at the top of the furnace.

like i said b4:* it is not okay to side-vent a mid efficiency furnace from the factory without any kit designed to convert it to power-vent.* they must vent through vertical chimneys, the exhaust rises up, it doesn't get forced out by the fan. the inducer in mid efficiency furnaces isn't powerful enough to maintain a positive pressure in a 6" diameter pipe.


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## yuri (Nov 29, 2008)

Wrong, there were a few 80% efficient furnaces side wall vented where I am. York had the Concept 2000 in the 80's and I believe Olsen had one. I did not like the termination kit as the fumes could stain the stucco or siding but they were legal. The inducer has some power and as long as the pressure switch in the furnace is proven then it is safe to use.

However I am not sure if Lennox has such a kit as I am not in the US and we don't have anything but high efficiency units in Canada now.


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## beenthere (Oct 11, 2008)

That termination is a code violation. B vent requires a 1" clearence to combustibles. Your vinyl siding is combustible, let alone any framing under it within 1" of the B vent.


Next, B vent is for negative pressure draft systems only. So even if your furnace were to be approved for side wall venting, B vent is not the proper type of vent pipe to use.


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## yuri (Nov 29, 2008)

True, the York etc used a stainless flex pipe and not B vent. B vent is not airtight. However I don't know if they still allow that stainless flex or sidewall direct venting as I am in Canada. IMO it is a bad idea period.

Usually we would run a B vent chimney outside the house and chase it in (enclose it ) if we had to go thru the side and there was no existing old chimney to use.


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## nutshellml (Dec 14, 2015)

Here's a picture of the top of furnace. Model is SL280UH090V48B-03.


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## nutshellml (Dec 14, 2015)

Picture


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## user_12345a (Nov 23, 2014)

> Wrong, there were a few 80% efficient furnaces side wall vented where I am. York had the Concept 2000 in the 80's and I believe Olsen had one. I did not like the termination kit as the fumes could stain the stucco or siding but they were legal. The inducer has some power and as long as the pressure switch in the furnace is proven then it is safe to use.


unless it's specifically approved by the manufacturer i don't think it's safe or right whether the switch stays closed or not.


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## yuri (Nov 29, 2008)

Do you even know what the pressure switch is legally for?

It is to prove there is enough air thru the burners and heat exchanger for safe combustion and nothing else. The furnace could not care less what type of vent it is connected to or even if it connected to one.

We ran furnaces w/o chimneys in a greenhouse to give them CO2 and moisture for the plants and heat and it was legal. Plenty of makeup air and draft in a greenhouse and like running a propane forklift in a warehouse it can be done.

*Nutshell*, IMO your guy is a hack and that setup will not be allowed. Only safe or legal way to use B vent is to run a chimney up the side of the house and enclose it. There used to be a system to sidevent it with a special flex pipe and fireplace type termination kit but I don't know if that is allowed in the US anymore. You should find out from your local gas inspector what the code is for side venting.


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## nutshellml (Dec 14, 2015)

@yuri thanks and I will bring this up. We moved the furnace to the other side of the basement (away from chimney) for various reasons. So basically, this is not up to code, so 1) it either needs to go back to where it was (since venting to chimney from current location is not an option), 2) buy high Efficency furnace that allows for side venting (which I do not want to do), or 3) find out if Lennox makes an add on blowe/fan? (Not sure if that's an option)


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## yuri (Nov 29, 2008)

They won't have a add on blower fan but, and I highly doubt it, there may be a sidewall vent termination kit.

There is a special Tjernlund ventor fan which can go between the furnace and outside but it is very noisy, expensive and has to be interlocked to the furnace wiring and can fail.

Used rarely and only as a last ditch resort.

http://www.tjernlund.com/gassidewall.htm


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## roughneck (Nov 28, 2014)

Was this a side job by someone? Or did a company do that?


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## nutshellml (Dec 14, 2015)

A company that came recommended and I felt comfortable after talking to many others. We took out permits so if it doesn't fly it will have to be fixed.


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## roughneck (Nov 28, 2014)

nutshellml said:


> A company that came recommended and I felt comfortable after talking to many others. We took out permits so if it doesn't fly it will have to be fixed.


It doesn't need to be fixed as much as it needs to be removed and redone. 
There's nothing right about any of it really. And when your dealing with carbon monoxide, you really want things done properly. 
I've seen clueless building inspectors pass things like that for no apperant reason.


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## roughneck (Nov 28, 2014)

That picture you took, is that the furnace moved to its new location? Is the work complete in that picture?


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## nutshellml (Dec 14, 2015)

Yea the furnace is in the new location. It vents up the runs along ceiling on an angle and out the side. The job isn't completed yet, maybe about 3/4 done. I have electrical and plumbing inspections for other work and will inquire when they are there about the venting. 

Problem is moving it back isn't an option because of how the ducts were all run. Would the only other option be a high efficiency furnace? Or is that not even and option?


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## user_12345a (Nov 23, 2014)

find and check the install manual. 

there may be a way to do it legally as the others have said. (possibly with a external power vent), consult whoever's inspecting the gas work.

B vent is an obvious no no because it's not air tight, can't be safely used under positive pressure.

would be a shame to throw away a nice modulating furnace. (and i'm betting it's being controlled by a single stage thermostat -> total waste)

a real shame the extra $500-1000 wasn't spent on condensing model. why contractors sell otwo stage/modulating only to go for 80% is beyond me.* (well, unless you're in texas or something and doing it for the ecm blower) 

*oh i actually know why. it's less work with an existing chimney and the high end furnace gives the sleezy salesman more commission. it's all about what brings the most money to everyone involved at your expense.


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## nutshellml (Dec 14, 2015)

Well the furnace was the only thing there when I bought the house, was new (2014) and variable speed. I did by a two stage thermostat to take advantage as much as possible, but didn't want to get Lennox thermostat for various reasons. 

ill have to see what inspector says.


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## BayouRunner (Feb 5, 2016)

yuri said:


> Looks totally illegal and bush league to me. it.


That was a very nice way to put it. If that vent is the way the contractor left it. You need another contractor period. He does not deserve a second chance. We don't have basements here but I would think the pipe would have to be taken to the roof if it was in our area. Certainly wouldn't be just stuck through the wall like that and touching the siding. Requires 1 inch clearance. I've just not seen anything like that. My advice is to run not walk away from that contractor


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## beenthere (Oct 11, 2008)

A sidewall power venter can be installed. 

The venter gets installed on the wall, and the B vent ran to it. The venter makes teh flue negative pressure again. The venter is wired up to interlock with the furnace. meaning that if the venter fails, the furnace won't run. At least not in heat mode.

http://www.tjernlund.com/gassidewall.htm








Save​


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## beenthere (Oct 11, 2008)

https://www.questargas.com/ForEmployees/qgcOperationsTraining/Furnaces/Lennox_SL280UHV_IOM.pdf


Page 15 states your furnace is not approved for horizontal venting. Most AHJ will allow it with the use of a power venter.


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