Heated Garage

[Nick M.]

In the heat of the summer I probably should not be thinking of a heated garage but as winter looms large I am considering the possibility of installing an HVAC system in my garage to not only provide heat in the winter but to also provide AC in the summer. What concerns me is the prospect of having a furnace in my garage with gas heat and an open flame, so to speak. My concern is that the old corvettes always seem to give off the smell of gasoline fumes after running the engine and I wonder about the safety of it all. I know many car owners have a heated garage and I have seen overhead gas heaters in commercial garages so I'm wondering what feedback you may provide about the pros and cons of it all when you consider the safety aspect.

[Dick W.]

Re: Heated Garage

Nick, check the building code in your area, but I think, for vehicle storage and repain, that the accepted minimum distance from the floor to the firebox of an open flame heater is 84"

[Dave F.]

Re: Heated Garage

Dick is right about checking your building code. Issues of solvents, paint, and other flammables typically found in garages also come into play. You may be able to build a small furnace room adjacent to your garage and duct through the wall to condition your space. That way your exterior wall separating the garage from your gas furnace would serve as a firewall. Another possibilty would be using a heat pump, eliminating the open flame.

[Nick M.]

Re: Heated Garage

Dick

I'm familiar with the codes in my area and there is no minimum clearance required for installing the furnace. Doesn't mean that anything less than the 84" you suggest is safe!

[Gary C.]

Re: Heated Garage

Nick, not sure of your state but most have adopted the International Residential Building (IRC) or California Building codes. All heaters have fresh air vents for both air circulation and combustion and are not supposed to draw any air from inside the building. Only air drawn from inside the building would be for recirculation by the HVAC system. In alot of North Texas homes the water heater and HVAC are in the garages. There's an HVAC system in my shop enclosed in a closet. Closet is sealed to the shop. Twelve inch vents to the outside for combustion air and four inch for fresh air for recirculation. Hope this helps. As someone pointed out you could do a heat pump if your temp doesn't get below 20 degrees. Good luck, Gary....

[Jim D.]

Re: Heated Garage

Typically an ignition source must be 18" above floor level. That applies to water heaters and furnaces in an area where autos are stored (garage). Gasoline vapors are heavier than air and tend to disipate below that level before reaching their LEL (lower explosive limits).

[John D.]

Re: Heated Garage

HI Nick, My garage and shop are heated by an electric furnace and 3 ton AC unit. I can make ice cubes in the garage if I want to. Anyhow I realize some think that gas is cheaper but today that is not really the case and if it is so what. For safety reasons I went with the electric. Very efficient and zero maintenace except for filters.
With some of the chemicals I experiment with I wouln't think of using a gas furnace. Lately though I am going enviromentally safe and using non toxic-non flammable POC chemicals. Take care of the 63. John

[Bill M.]

Re: Heated Garage

I installed a between-the-studs 50,000 BTU gas furnace thirty years ago. It draws combustion air from outside and the pilot is isolated from the garage. These furnaces are designed to heat the upstairs area of a bungalow. It works great. I'm thinking about A/C...

I found rivers of rust in my 396 intake ports one spring after pulling the intake manifold. (The engine had not been run since fall.) I keep the garage at 50 degrees during the spring and fall to eliminate the condensation that caused this problem. In the winter, I let the garage go to ambient (Michigan). I haven't seen any significant $ hit.

[Chuck R.]

Re: Heated Garage

Of course you can side step all of this by going the AC/heat pump route where all you'll have is an air handler in the conditioned space.

If you have the option, a separate "mechanical room" attached to the garage area ducted into the conditioned space would be my option.

The machinery would stay relatively clean and your combustion process is removed from your "other" ignition sources. Make it large enough, and you could also house your air compressor in it as well. How many air compressors do you see in body shops that don't have several layers of paint overspray, dust and "other" foreign matter stuck to them. Not to mention the ones that don't have a fresh air sourse to pull from. Other benefits would be picking up valuable floor space and reduced Dbs
I'm real good at spending other people's money

Up here in the rust belt of New York another option is being considered and that's radiant heat in garage floors. But, your talking a boiler running on fossil fuels PLUS numerous gallons of antifreeze in the lines just in case the system go's down in sub zero temps. If your talking an existing garage floor then this isn't even an option.

What I wouldn't give though to throw a piece of cardboard down on my garage floor in December and have it be a cozy sixty or so degrees

Chuck

[Dave F.]

Re: Heated Garage

Of course you can side step all of this by going the AC/heat pump route where all you'll have is an air handler in the conditioned space.

If you have the option, a separate "mechanical room" attached to the garage area ducted into the conditioned space would be my option.

The machinery would stay relatively clean and your combustion process is removed from your "other" ignition sources. Make it large enough, and you could also house your air compressor in it as well. How many air compressors do you see in body shops that don't have several layers of paint overspray, dust and "other" foreign matter stuck to them. Not to mention the ones that don't have a fresh air sourse to pull from. Other benefits would be picking up valuable floor space and reduced Dbs
I'm real good at spending other people's money

Up here in the rust belt of New York another option is being considered and that's radiant heat in garage floors. But, your talking a boiler running on fossil fuels PLUS numerous gallons of antifreeze in the lines just in case the system go's down in sub zero temps. If your talking an existing garage floor then this isn't even an option.

What I wouldn't give though to throw a piece of cardboard down on my garage floor in December and have it be a cozy sixty or so degrees

Chuck

Great thought on getting the air compressor out of the garage Chuck. I knew that trick - just forgot it

IF a new mechanical room is out of the question, another way to skin this cat is to install an exterior wall pack HVAC unit, similar to ones you see on construction trailors or modular classrooms that some school districts began using back in the 80's in California.

[James L.]

Re: Heated Garage

Nick

I'm in NJ and have had a gas heater mounted 7 ft off the floor for 10 yrs. It keeps the garage comfortable at 55 degrees in the winter. I use an 8000 BTU window air conditioner to control heat (78-80 degrees) and humidity (55-60 percent) in the summer. Jim

[John H.]

Re: Heated Garage

My attached garage is 2600 SF, super-insulated (including under the slab); I heat it (photo below) with a ceiling-hung Reznor power-vented forced-air gas unit heater with electronic ignition (no pilot flame), and cool it with a 42,000-BTU Mitsubishi "Mr. Slim" mini-split A/C unit - only required a 3" hole in the wall for the refrigerant lines and condensate drain line (click on link below):

http://www.villagephotos.com/pubbrowse.asp?folder_id=1411059

[Grant M.]

Re: Heated Garage

Nick,

I'm also about to have a heater installed in my garage (Ottawa winters can get chilly!) and have been talking to the HVAC contractor about options. His suggestion and based on what John Hinckley has in his garage (Reznor gas space heater), is for a separate combustion version of the Reznor heater (the firebox is completely sealed-off from the room being heated, draws air and exhausts to the outside). It's also electronic ignition (no pilot) and therefore there are no issues wrt solvent/paint use.

I agree with others' suggestion re: having the heater and/or air compressor in another room or shed for noise/dust control reasons, but it won't be possible in my case.

Good luck!

grant

[Wayne K.]

Re: Heated Garage

Also check with your insurance company as most do not allow open combustion heating units in a garage be it for heating of air or water.

[Chuck R.]

Re: By the way

I heat my garage (20' X 45') with a small hot air furnace I gleaned out of a trailer.

The advantage is that the air handler discharges hot air out the bottom of the unit throwing the heat across the floor where it's needed before it drifts up the the ceiling, it takes up very little space (2' W X 2' D X 6' H) and runs on a .5 gph nozzle making it very miserly on fuel as well.
The only dis-advantage is that the prior owner was a three pack a day smoker and everytime the blower kicks in the distinct odor of nicotine permiates the shop. This after five years of non-smoking garage use my friends.

Interesting how long that stuff can linger on certain surfaces huh?

Chuck