Heating Detached Garage?

[Scupper]

Looking for advise/options as to go about heating my 27x20 garage.

I live in beautiful(really)North Minneapolis in one of the standard post WWII homes, Story and a half erected in 1948.

Over the years I have added on to and for the most part, finished off the interior of the garage. I'm finding myself spending more time in the garage and have been heating it with electric($220$)and propane the past couple years.

I will guess the garage is roughly 50 feet from the house. I truly would appreciate any and all thoughts as to heating.

Scott

[BoxMN]

Did you insulate it, and use proper vapor barrier? If so, probably add a hanging gas furnace (or old house furnace) and you are set. If you didn't insulate properly, then you more advice than I can give You will love it though, my garage is 50' away and I use my old home furnace. Works great.

edit - at 20x27 you don't need a full home furnace. Make sure you have good insulated overhead garage door (mine is 2" insulated steel doors) and good weatherstripping too.

[Tom7227]

I just finished putting a natural gas furnace in my attached garage on Saturday. I bought a used house furnace off a-sales-site for $175 and spent another $350 on copper tubing, a new plenum and grates, thermostat, vent pipe, shut off valves, hangers for the pipe and electrical hookup stuff. I am very happy with what I have. Lots of folks will suggest a hanging unit but I think it would have cost $550+ on one. The other stuff is going to be spent no matter what furnace you have. Check the list and you'll find a wide variety of rigs for sale.

[chad austin]

If you do use a home furnace be sure to elevate the furnace as far as possible off the floor.

When I changed over my insurance they came out to the house and did a walk around the property and noticed the garage was heated. the only thing he said was that he was surprised the the furnace was elevated the required 15" off the floor to keep gas fumes from being pulled into it.

[Tom7227]

I have to correct my information. I spent $350 at HD for the pipe etc. and another $125 for the plenum. I have a cement ceiling and block wall in the garage and so I had to buy Tapcons, hammer drill bits and some expensive hangers to get the copper tubing where it needed to go. The flexible copper tubing was $105 for 60 feet of 5/8 OD. It would have been cheaper by a bit if I had gone with steel pipe but by the time you add in all the fittings and consider the extra effort/trips to get pipe cut etc. the tubing made more sense to me.

[Tom7227]

Chad,

Someone mentioned this when I was asking questions about my project. I checked and the burner on the furnace I got is 18 inches from the floor and I have the rig up on a 4 inch slab. Is that good enough?

Thanks.

Tom

[Jarrid Houston]

Thinking about doing mine too, but I am going to go with a wood stove...

[Scupper]

Thanks all for replying.

With the shared advise and researching this subject I'm not quite sure as to how I would go about plumbing a supply line from my home source(Natural Gas)out to the garage. I'm certain that a professional will be needed for some of this work as well as permit.

Any other thoughts...

Thanks,

Scott

[chad austin]

Chad,

Someone mentioned this when I was asking questions about my project. I checked and the burner on the furnace I got is 18 inches from the floor and I have the rig up on a 4 inch slab. Is that good enough?

Thanks.

Tom

Tom,

The burner really doesn't have anything to do with it, you want the fresh air intake off the floor 18" so the potential for gas fumes being sucked into the "combustible" air intake. Keep in mind this is a safety issue in case your heat ex-changer ever cracks and at that point it would be an open flame exposed.

I don't remember what the minimum requirement is but I have mine at 18" off the floor.

[MNice]

Here is the code section with the 18" requirement. Any part of the burner, anything that may cause a spark. Nothing to do with the return air. You can have the return air as low as you wish. All about ignition of flammable vapors from gas, etc.

305.3 Elevation of ignition source. Equipment and appliances

having an ignition source shall be elevated such that the source

of ignition is not less than 18 inches (457 mm) above the floor

in hazardous locations and public garages, private garages,

repair garages, motor fuel-dispensing facilities and parking

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.

[cavalierowner]

From what I recall from designing MnDOT and city truck maintenance buildings, anything capable of a spark or glow had to be a minimum of 18" off the floor. On a conventional furnace the burner may be enclosed, but don't forget about the blower motor that is in the bottom of an upflow furnace. BUT, I am not a mechanical engineer, so I may be wrong. I would suggest talking to the inspector when you apply for the permit so you don't have to redo anything or blow yourself up.

[chad austin]

Here is the code section with the 18" requirement. Any part of the burner, anything that may cause a spark. Nothing to do with the return air. You can have the return air as low as you wish. All about ignition of flammable vapors from gas, etc.

305.3 Elevation of ignition source. Equipment and appliances

having an ignition source shall be elevated such that the source

of ignition is not less than 18 inches (457 mm) above the floor

in hazardous locations and public garages, private garages,

repair garages, motor fuel-dispensing facilities and parking

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.

I generalized my reply and I shouldn't have . On the furnace in my garage the "return air" or intake is the lowest part of the furnace (also where the blower motor is located) which is why I said 18" for the return air. What I was trying to get across is that when I installed my furnace, I didn't want to leave anything to chance so I made the very bottom of the unit 18" from the floor.

[MNice]

Chad, that is the best way, build a 18" platform & you're done.

[JohnMickish]

A little insight on the 18" rule. In any building where vehicle storage or maintenance can take place, 18" up from the floor is considered to have the potential of becoming combustable with fumes. If you have a pit in the floor that entire area is considered hazardous as well. Even in a residential garage.

[Scupper]

25 years ago, maybe longer I learned the 18" inch rule/regulation as I burned wood to heat the garage. I was out there on New Year's day watching the bowl games on a small black & white TV while changing out a starter on my truck.

I heard the siren's nearing which is quite normal to this day in my neighborhood and didn't think twice about it until I heard the diesel engine and other commotion outside the garage door. I opened the door as the firefighters were approaching. I invited them in and we had a short discussion as to the dispatched call from a concerned neighbor as to a possible garage fire-smoke from Chimney.

One of the fellah's measured the height of my 55 gallon burner barrel and exclaimed that it was 25 inches off the floor. Our attention then turned to the game on TV with small talk as to where location of ignition source and various explosive fumes linger.

So, I have had that knowledge stored away for some time now and I do appreciate the friendly 18"reminder here but can anyone explain to me the process of going about plumbing a "Gas Supply" line some 50' feet to my Detached garage?

Thank's.

Scott

[Tom7227]

So, I have had that knowledge stored away for some time now and I do appreciate the friendly 18"reminder here but can anyone explain to me the process of going about plumbing a "Gas Supply" line some 50' feet to my Detached garage?

Well I suspect that it starts with a shovel.

Seriously I think you could use plastic pipe because that's how NSP got the gas to my house. What I don't know is if a layman can get the bright orange stuff or what type of fittings to use. Maybe calling the gas company and seeing if they would run it for you? 50 feet with I suspect a minimum 18 inch depth is a lot of digging. Rent a Ditch Witch is what I would do. I did it to put a drain tile outside once and it was a tough rig to run - a rig about 1/2 the size of a refrigerator that had a chain saw built in that cuts dirt. Not sure if it's really a DIY project unless you're young and like to sweat.

Just saw that you live in Mpls. Good luck with this there.

[chad austin]

Gopher State One Call (800) 252-1166 - This would be the first thing you should do before you put a shovel into the ground.

As far as the piping goes, there is copper pipe that is rated for burial.

I also like to back fill the trench about 6" on top of the pipe and put down a red "warning" plastic tape (like the yellow stuff the police use for crime scenes). Then fill the rest of the way.

The reason for this is just in case you or the next home owner decide to dig there.