Thread: External Air Source

I thought that all of the newer manufactured fireplaces had an external air source for combustion. The house today was built in 2005, and did not have an exterior source for the combustion air. The model was a DESA B36, which has an optional external air kit, but the model installed did not have it. Are other inspectors seeing new factory fireplaces without external air. The company rep said that to operate the fireplace the glass doors must be left open. Seems pretty lame to me as far as energy efficiency.

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I bet those glass doors should be removed if it is not setup for a direct vent. I have never seen a ventless FP with fixed glass doors. Only the direct vents have the glass doors, that I have seen.

Yes, many areas still allow ventless FP's to be installed. I see them all the time in new construction.

Scott, Do we know for sure this was a ventless type. Or is just the lack of"combustion air kit" at issue?

My fault on the description. It is a wood burning factory built fireplace. It does have a flue vented through the roof. I originally thought that the flue was the source of combustion air, because it looked like a direct vent flue at the top. However there was no lever to open or close the incoming combustion air like I normally see. The damper can be opened and closed, but that was all that we could find.

I guess they will be cracking a window in the same room then.

IRC R1005.1

Bob

Originally Posted by Bob Harper

IRC R1005.1

Bob

Isn't R1005.3 the applicable one, being as that is wood burning?

- R1005.3 Solid-fuel appliances.

Factory-built chimneys installed in dwelling units with solid-fuel-burning appliances shall comply with the Type HT requirements of UL 103 and shall be marked “Type HT and “Residential Type and Building Heating Appliance Chimney.”

- - Exception:

Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL103 and shall be marked "Residential Type and Building Heating Appliance Chimney.”
- - Chimneys for use with open combustion chamber appliances installed in buildings other than dwelling units shall comply with the requirements of UL 103 and shall be marked “Building Heating Appliance Chimney” or “Residential Type and Building Heating Appliance Chimney.”

Yes, the IRC 1005.1 is what I was referring to. I thought all wood burning factory built fireplaces were required to have an external source of combustion air. However, this one did not. Either we were not under 2003 IRC in 2005 or the AHJ didn't see it in the house. Hard telling here.

Are other inspectors seeing new factory built wood burning fireplaces with no external combustion air?

IRC 2003 R1005.1
Factory built or masonry fireplaces covered in this chapter shall be equipped with an exterior air supply to assure proper fuel combustion unless the room is mechanically ventilated and controlled so that the indor pressure is neutral or positive.

Pretty cut and dried without going further, seems to apply to all fireplaces, not just solid fuel.


I don't see the wording you mention in my 2003 IRC, is there a change in the 2006 Jerry?

Either we were not under 2003 IRC in 2005

That was not new to the 2003 according to the margin markings in my 2003 book, so it appears to have been inplace in the 2000 version also.

UL 103 HT applies to 2,100F rated chimneys for woodstoves and hybrid fireplace/ woodstoves. The typical factory built fireplace is listed to UL 127, which normally uses a 1,700F chimney but with an optional 2,100F test.

Bob

Originally Posted by Jim Luttrall

IRC 2003 R1005.1
Factory built or masonry fireplaces covered in this chapter shall be equipped with an exterior air supply to assure proper fuel combustion unless the room is mechanically ventilated and controlled so that the indor pressure is neutral or positive.

I don't see the wording you mention in my 2003 IRC, is there a change in the 2006 Jerry?

Yes, that is the difference and that is why we need to specify year of the code reference - this is from the 2006 IRC.

- R1005.1 Listing.

Factory-built chimneys shall be listed and labeled and shall be installed and terminated in accordance with the manufacturer’s installation instructions.

The 2006 has a completely different R1005.1 than the 2003 IRC has.

I say "potatoes" and you say "tomatoes", and everyone looks at as like we must be crazy.

R1005.1 in 2003 is talking about "tomatoes" and R1005.1 in 2006 is talking about "potatoes".