How to heat a home garage

Thread from 2010:

I have a cookie cutter house built in 2002 in the suburbs. It has a two car garage that thankfully has a single big garage door and does not have a pole in middle. I would say it measures 20x20' and the ceiling is maybe 8' tall. The garage door does not seem to be insulated. Two sides of the garage butt up against the interior of the house and one wall and the door face the cruelty of Mother Nature. Last winter was very cold here in Nebraska and it really curtailed the amount of car work I could accomplish. I don't want to be crippled by cold again this year. How can I best heat up my garage for car work? I don't want to pay to heat it all the time, but I also don't want to have to wait 8 hours for it to warm up. More importantly I don't want to die from carbon monoxide poisoning. Are the garage door insulation kits from the big box hardware stores effective? I already have a whole bunch of those foam pads to put down to add a layer of insulation between the floor and me. I don't want to make it so warm that I can wear shorts, I just don't want to see my own breath. It generally doesn't get below 0* Fahrenheit. Should I look for electric heaters? Propane? Kerosene?

I have a feeling that drafts around your garage door seal will be a big issue.

I'm not sure how to address that and still keep the door functional...but I just thought I'd point out that consideration.

Thanks,
Clem

I insulated garage doors with the styrofoam home insulation sheets, like ~1" thick, glued onto the inside. It really helped a lot, but that was to keep heat out, not in (Texas). The insulation sheets were cheap.

A kerosene heater is going to need to be vented so you don't kill yourself. Probably propane too. Plus watch the fire around gasoline. I've worked in fairly cold weather here (~10F-15F) using a shop light stand with 2 500 watt lamps and an electric space heater. It wasn't too bad, when dressed appropriately in a Blizard-Pruf overall and cotton work gloves, thermal socks, watch cap....

My last house had a similar situation and had I stayed in it I would have done the following:

1) Add insulation!!!! 10000 BTUs won't do you any good if they're escaping from every crack and crevice. A fully insulated door would be money well spent. You would be amazed how much nicer it is in the summer too.

2) Talk to an HVAC contractor. Since its a newer house it likely has central heat and A/C. Depending on how your ducts are laid out you might be able to add a few in the garage fairly cheaply and have not only heat but A/C to boot. Now that the garage is insulated this makes a whole lot more sense.

Search around. There are kits to help close off the sides of the garage door to keep draftiness at bay while still letting it work.

Does your house extend over the garage? that will help with heat retention and will reduce the number of BTU's needed.

I use a 4000 watt, 240V heater from Northern Tool (looks like a little red cube) that does a good job of warming up my 1.5 car attached garage w/ 10' clg within an hour or two. In my g/f's garage (3+ car detached with gapping stairwell into the attic), it's pissing into the wind and I use 1 or 2 propane radiant heaters and dress warmly.

Insulation is key. We're working on tighening up the g/f's garage, although what I'll do for heat afterwards is up for debate since I won't be able to use the propane heaters once the natural chimney through the attic is closed off.

I bought the best insulated doors available when I built my garage and I don't really think that they make much of a difference.

I have a propane torpedo that does a pretty good job, but I'm always worried about CO and it's so loud that I usually run it for about 15 minutes when I'm not out there, then turn it off and go to work. If you're laying on the garage floor, heat won't make much difference, unless it's radiant heat in the concrete.

I used a natural gas radiant heater in my house when I was living in it and working on it at the same time (though it was too cold to work on it much).

This said it was good for 300 square feet (though they have larger ones). It didn't have a thermostat (it was on or it was off). It put out good heat for my small room, and was less expensive to run than an electric space heater. I bought it off ebay. just search "radiant" heater in whatever fuel source you prefer.

Clem

I keep thinking that a few old radiators in a glass enclosure + and old heater core and insualted lines would make a good DIY supplamental solar heater.

Good point. If you have natural gas in the house, I'd probably install a suspended garage heater. I'd love one for the g/f's garage, but it would require trenching a new line from the house. You can also run into local code issues trying to DIY an installation like this.

alfadriver wrote: I keep thinking that a few old radiators in a glass enclosure + and old heater core and insualted lines would make a good DIY supplamental solar heater.

I've looked into that. The water temps won't get hot enough for the radiators to do much. Solar radiant heat works in floors because the required water temps are roughly 60 degrees lower.

In reply to TreoWayne:

I use radiant floor heat, and will never use anything else. However, before I decided to use it, I bought two used Enerco 40k infra-red heaters that run off of natural gas. I'd like to sell them, so contact me if you are interested. I can send you pictures. They are similar to the one in this link, and I would like $150 each for them, which is what I paid. The beauty of these is that they heat objects (like your floor if you aim it that way), not the air, so things heat up fast, and they don't need vented.

http://www.enerco.com/product.aspx?groupid=0&catid=76&id=375

When I bought my current house, it had garage doors that were insulated with sheets of blue styrofoam. For various reasons, we replaced them with new, factory insulated ones that sealed properly. BIG difference.

Insulate the outside walls, garage door and most importantly the ceiling (heat rises), and weatherstrip all doors and windows.

Any sort of combustion heater (gas, propane) must be vented. People do use non-vented heaters but that doesn't mean they're safe.

Electric heaters may be worth considering; they are generally cheaper to install but also generally more expensive to operate. If you have cheap electric rates and don't intend on heating the garage 24/7 they can make sense. Electric unit heaters will heat the area up pretty quickly.

Don't try to tie into the house's existing forced air HVAC system, for two reasons: you need a fire barrier between the house and garage, and in addition it's a good way to introduce carbon monoxide into the house (along with various garage smells.)

Stuart makes a very good point about tieing into the central HVAC system. Pretty sure this illegal in most places.

When you actually look at the electric rates on your bill, running a 4KW heater for a few hours doesn't really cost that much.

I went with a new insulated garage door and insulated/drywalled the outside walls/ceiling. Made IMMENSE difference.

Old drafty garage door will be a PIA to fight against... just never open it and seal it with tape/insulation? :)

stuart in mn wrote: Any sort of combustion heater (gas, propane) must be vented. People do use non-vented heaters but that doesn't mean they're safe.

Not so. The heaters I mentioned above are natural gas powered and do not need a vent.

I use a portable propane heater.. thankfully my garage is VERY draft (roof vents you can see out of) so I do not need to worry about killing myself from a lack of O2. Because I rent it, I really can't insulate it though

Two of those insanely bright halogen work lights always kept me warm when I actually was permitted to use the garage at my parent's house. They throw a ton of heat. Again, not like I could wear a short sleeve shirt, but only in a sweatshirt I was warm. Plus you have crazy extra light.

Once I changed the oil outside on the driveway when it was 15*. It was fun!

bravenrace wrote:

stuart in mn wrote: Any sort of combustion heater (gas, propane) must be vented. People do use non-vented heaters but that doesn't mean they're safe.

Not so. The heaters I mentioned above are natural gas powered and do not need a vent.

LIke I said, they may be non-vented but that doesn't mean they're safe. Without venting, any combustion products (i.e. carbon monoxide) stay inside the room. If they're used in a well ventilated area they may be okay, but I still wouldn't recommend them.

I put an insulated door on the Garage Majal when I built it, and got maybe halfway through the insulation etc before other things just took too much of my time. Maybe one of these days...

The garage attached to the house was insulated on two walls and in the ceiling (there's a finished room overhead), the third wall is not insulated but is Sheetrocked. It has an insulated garage door (had to replace it last year, that cost ~$850.00) and it stays a good bit warmer than the outside, probably at least 30 degrees. I'd say jump on that first, if you can't swing the cost of a new door at least weatherstrip between the panels with foam, put those contact strips around the outside and seal it to the floor. Foam boards won't be a lot of insulation in the panels but will be better than nothing. Insulate and Sheetrock the outside wall, if the area over the ceiling is not insulated (not uncommon) then get some of that blow in stuff and insulate the ceiling.

If there are heat pumps in use in your area, you might look into one of these.

The split units put the air handler on the wall and the condenser outside, they are pretty reasonably priced. As an added benefit with that, you will have A/C in the summer and REALLY be the envy of your friends. If those are a bit too expensive, assuming you have a window in the garage you can get an 'all in one' which looks like a big window AC unit and again be the envy of your friends. Those can also be instaled without a window by cutting a hole in the wall, but this will need to be done properly to avoid water damage, etc.

I used the Menards door insulation kit last winter here in Minneapolis and the garage temp jumped a consistent 30 degrees. The kit I bought has a foil face on the one side, and I think that does as much as the foam. Just the engine and tire heat from the car pulling in would raise the temp in the garage enough to be comfortable for an our after it shut off.

I use a propane "sheetrock heater" in mine. Fire it up full blast with the door shut to warm up everything in the garage, shut it off and open the door a foot for a minute to blow out the CO, then leave the door to the house open while I'm working out there. Worked for me.

Off topic: Where in Nebraska are you?

I have a thru the wall motel-type heater/ac & plenty of insulation. More than adequate for NC winters. Might work in Nebraska.

Here's the thing about non-vented heaters. (MR. Heater former warranty repair tech here)

Ever wonder why propane forkilfts are ok for use in a warehouse?

Propane requires enough oxygen to burn that it will go out before you do.

That's why they're UL approved for indoor, non-vented applications.

I use a Mr Heater Big Buddy in my shop and a Buddy in my camper. I've seen the flame go out an gone "huh, must've blown out" then it wouldn't re-light.

Open a few windows for a few minutes and the heater re-starts no problem.

Propane indoor heaters are VERY sensetive to oxygen levels.

Shawn

I am in Omaha.