Outside Air Kit (OAK) - Insulate Pipe or Not?

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mminor

Member
Sep 11, 2015
142
Long Island NY
Hello. I am adding a bump-out zero clearance fireplace to my existing home (floor plans attached).

Can you wise ones please recommend whether I should be using insulated pipe for the outside air pipe which will be 2.0 - 2.5 feet in length? What are the pros and cons of insulting it versus not insulting it?

Thanks for everyone's help!

Matt
 

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Don't just insulate it, insulate with a vapor barrier. You'll get tonne of condensation and icing on it if you don't.

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Don't just insulate it, insulate with a vapor barrier. You'll get tonne of condensation and icing on it if you don't.

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It's those same reasons the guys who installed my FP30 insulated and wrapped with a vapour barrier.


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I was gonna start a new thread but figured this would apply to your question as well so hope you don't mind me hijacking it.

Anyone have any suggestions on how to cure this issue? It's on a focus 320. The outside air kid is insulated but the side of the fireplace still ices up with cold weather. Any suggestions?

Outside Air Kit (OAK) - Insulate Pipe or Not?
 
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I was gonna start a new thread but figured this would apply to your question as well so hope you don't mind me hijacking it.

Anyone have any suggestions on how to cure this issue? It's on a focus 320. The outside air kid is insulated but the side of the fireplace still ices up with cold weather. Any suggestions?

View attachment 192121
What exactly are we seeing? Is the sheet metal where the duct passes outside? You say it is the side of the fireplace but it seems that the heat from the fire would be melting the ice where the metal is.
 
Sorry here's a better picture. Yes it's the side of a zero clearance rsf focus 320 fireplace. The outer sheet metal of this fireplace stays very cool while there is a fire, as you can tell from the ice on the side even when there's a fire. In fact I think having a fire makes it worse as it then draws more air through the outside air kit.

Does anyone else have this issue or does the outside air ducting in most zero clearance fireplaces stay hot enough to keep ice off? Keep in mind I'm in rural Manitoba, this week has been highs of -20c (-4f) and lows of - 33c (-27f)


Outside Air Kit (OAK) - Insulate Pipe or Not?
 
So all of the issue is on the outside of the fireplace sheet metal? Insulation should do the trick. Anyone have a reason why he can not insulate the side of the housing here?
 
Well the only reason I haven't is that sticker on the side that says "1/2 clearance to combustibles" . The best insulation would be sytofoam or spray foam for this area, both combustible.

With fiberglass I would imagine I'd need to vapor barrier it too so the insulation doesn't just get soaked.

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Roxul bat insulation and a vapor barrier would be best. If it is well insulated (you need more than you have on that air inlet with how cold it gets) you will not have condensation build up. That air inlet is poorly insulated, would you tolerate about an inch of insulation in your house wall? You effectively have a wall there. Once the cold air gets into the fire the coldness is not a big issue. But outside the fireplace it is cooling the (closet?) area as air is moving in.