Garage Furnace Intallation

[Jason Hanko]

Hi everyone,
Just want to take a quick poll of any of you who might be famaliar with this...
Im installing a furnace in my garage to help with these 2° days. The furnace is one of those in-wall units designed for apartment buildings and other small spaces. It does not have an enclosed burner, and my HVAC guy said that often in garages there is a minumum height from the garage floor that the burner must be to avoid incidents with things like gas fumes. He didn't know the required height, so I called our town's building inspector.
The building inspector (who Im fairly sure I woke up with my call - at 10:30am on a Wed) told me that it would have to be 4 feet from the floor. FOUR FEET?
I know local codes are going to be different from place to place, but Ive done a lot of searching on the interweb and every other code I can find says 18''. Anyone have any thoughts...?

[Mitchell Andrus]

I'm willing to bet the manufacturer or a qualified installer will know your state's/NFPA regs.

4 feet may not be unreasonable for garage space without an active air change system. 'swhy you don't see these in commercial shops very often. Overhead units are 7'+ off the floor.

[Rob Wright]

Jason -

I wanted to install a smaller water heater in my garage in T of Middleton this year. Building inspector said open ignition sources to be a minimum of 18" above garage floor....

This should be an easy find in the CODE CHECK books that are at Home Depot. I know that they list many of the gas codes in the plumbing book - it may be worth a shot...

If he insists on 4-ft - ask to see the code - either IBC or UDC

Lov'in the plowing job on Madison streets Today! - Rob

[Matt Ocel]

Furnace -

International Residential Code -

G2408.2(305.2)
Equipment and appliances having an ignition source shall be elevated such that the source of ignition is not less than 18 inches (457mm) above the floor in hazardous locations and private garages. For the purpose of this section, rooms or spaces that are not part of the living space of a dwelling unit and that communicate directly with a private garage through openings shall be considered to be part of the private garage.

So 18" is the magic #.

In the case the manufactueres requirements are more stingent, follow there requirements.

[Duncan Horner]

Local jurisdictions are free to implement more stringent requirements, so regardless of what the national codes say, it's what your jurisdiction says that goes.

Ask him to show it to you in your city/town's codes.

[Russ Massery]

I have one in my shop also a garage. Code is for OPEN ignition or flame. My unit a Williams is a close combustion unit. It has a double wall flue that also brings in combustion air though inside pipe. Exhaust out the outside wall of the pipe. The code is mainly for hot water heaters. Code here is 18" also.

[Rollie Meyers]

I have one in my shop also a garage. Code is for OPEN ignition or flame. My unit a Williams is a close combustion unit. It has a double wall flue that also brings in combustion air though inside pipe. Exhaust out the outside wall of the pipe. The code is mainly for hot water heaters. Code here is 18" also.

A regular wall furnace has a open flame.

BTW, if the water is hot why does it need heating?

[Jason Hanko]

Well I did some checking on my own, and found my city's building codes posted online... it basically referred me to the WI state building code. Read thru that and it said 18'' for open flame units such as my furnace.
Called the HVAC guy Im going to have check over the unit (I did the conversion from NG to LP myself, so Im definitely gonna have it looked over and fired up for the first time by a pro) and he said our local code is 18''. Just to verify he called the same building inspector I did, and HE said 18''...
So yeah, 18'' it is.
Gonna head out now and raise 'er up!

[Jason Hanko]

Aaand Done!
HVAC guy is coming to do final hookup and testing tomorrow morning.
I can almost feel the heat already.... brrr, almost...