NY: Does state code allow furnace to be installed without return duct?

[Patrick Maloney]

Just sitting in a closet with a louvered door?

tia,Patrick

[Eric in North TX]

I don't know about NY, but most places now require the furnace closet to be a solid door. The closet must be vented to a non habituated area, usually the attic, or the outside. The idea seems to be; to keep the unit from consuming all the air in a tight building, & leaving the occupants dead. Our code here allows the return to be just a grille under the furnace, no actual return "duct".

[Don Phillipson]

The local fire service may know off-hand. Your municipal building permits office has the most detailed information.

[EXT]

Caution, if the furnace is a fuel burning furnace, having the return air outlet at the furnace or even in the same room could cause it to create negative pressure in the fire chamber resulting in the flames drawn improperly outward towards the outside of the furnace or at minimum allowing the byproduct of combustion to be sucked from the furnace and circulated throughout the house. This would include carbon monoxide.

[Michael Dobony]

Ask your local inspector. This is how many trailer furnaces are.

[Bob]

It depends on the type of furnace and combustion air source. A key factor is whether a risk of negative air pressure exists which would often be the case with a forced air system. The furnace needs combustion air from somewhere; in many cases it comes from the attic. Mobile homes have a closed combustion chamber with air coming in from the outside. A clue is the sealed opening for the pilot burner.

In short, there is no definite yes or no answer. Your local building inspector may have a more definitive answer.

[Patrick Maloney]

Bob wrote in news:lN7Ok.6583$Ws1.1015 @nlpi064.nbdc.sbc.com:

Thanks for all of the responses...I'll call the local inspector.

It is a condensing furnace which uses PVC for intake/exhaust of combustion air from/to the outside of the building.

[Don Young]

A condensing furnace generally requires the vent and intake to be in the same general area to equalize the pressures. Otherwise wind, fans, combustion, and other conditions can cause pressure differences which will cause the pressure sensors to shut down the furnace. Check the installation manual for specifics.

Don Young

[Bob]

Whether or not the code requires or prohibits a louvered door, there are a few other potential considerations. A louvered door:

- allows waste heat from the furnace to help warm the room

- doesn't muffle furnace noise

- provides another place for dust to settle

[clare]

Not sure, but I think you guys are answering the wrong question. I THOUGHT he was asking about the cold air return. Combustion air is a totally different question, and if it is a HE condensing furnace with the 2 through the wall pipes, it is totally irrelevent to the question, no?

[clare]

In reply, the waste heat warming the room is a bad thing? My furnace, which DOES have a return duct, is out in the open for all to hear. The louvred door will hold a LOT less dust than a cold air return duct, and is a far sight easier to clean.

[Ed Pawlowski]

My impression also. Of course, the air has to move somehow, duct or not. My old house had a gravity system and while not ducted to the furnace, it did drop into the basement. You can't blow air into a room and not let an equal amount of air out.