How should I heat my garage?

Great forum here, have been reading for a couple weeks getting ideas for an upcoming project... namely, finishing off my garage. Hope you guys and gals can help me with the biggest question of the project.

It's a 20'x20' garage, built in about 1970. Ceiling height (when installed) will be 8' - currently 12' pyramidal hipped roof.

I plan to put in R-30 or R-38 above the ceiling, and R-13 in the walls (2x4 framing). Will install several soffit vents to keep 'attic' at outside temp. Concrete slab floor, uninsulated as far as I know. Old wooden garage doors are 7x8, probably will be replaced with new R-8 or R-13 doors. One small window (36"x36") and one 30" door will be replaced with low-E vinyls.

I have electric service in there, but only two circuits of 110v @ 20amp. Looks like the original owner may have done the wiring himself; needs to be rerouted, maybe completely replaced.

I am debating whether to upgrade the service to the garage; if so, I'd put in a 100amp subpanel with 220v. Or, more precisely, I'd have an electrician do it.

So, the next question is heat. I'm in Western Oregon and temps rarely go under 25F in the winter, with usual highs in the 30s and 40s and lows in the, well, 30s and 40s. I want to be able to work in the garage in the winter at a reasonable temperature for doing painting and such. 65F would be my target.

As I see it, I have several options (we don't have gas on site, and I don't want to deal with propane):

1.) Keep existing electrical, try to heat with small baseboard heater or space heater.

2.) Keep existing electrical, get a 12,000 BTU mini-split system with heat pump.

3.) Upgrade electrical to 220v, get a big ol' electric space heater or baseboard heaters.

4.) Upgrade electrical to 220v, get a 18,000 BTU mini-split with heat pump and aux heat.

5.) Find a second-hand pellet stove and install it in the garage. This would most likely be against code, but we already have a pellet stove in the house and so fuel would be easy to find.

Thanks for any feedback!

Anyone? :shrug:

My thoughts on the pellet stove are that it has several demerits:
1) Open flame source is dangerous when working with and storing chemicals (paints, solvents, etc)
2) Its not instant on (i.e. if you want it 65, you have to start the pellet stove a few hours ahead of time
3) Its not regulated via a thermostat so you'll have a garage temp of 45-50 unless the stove is on.
4) No summertime benefit - granted, where you are the summer temps may not be a problem, but humidity likely is if you want to paint.

Since you're getting an electrician to do a sub panel, I'd consider your option 4. Depending on what you were planning on running in the garage, you probably need 220 anyway (welder, compressor, etc.). Depending on how often you work in the garage, get a thermostat that fits your schedule (e.g. programmable to kick on the electric to get up to temp if you have a set garage time schedule).

Your #2 option maybe doable but without the resistance heat, you won't have quick recovery temps if you set back the thermostat for non-working hours. Also, you won't have any backup heat if the temps drop below the heat pumps capability (mid to high 30s).

I live in western WA state and heat a 24x24 pole building w/9ft walls, no insulation but it is sheet rocked, with a Cadet hot one heater. It is 220 volt and has a bracket to mount to wall. It does have a built in thermostat but I do not use the garage every day so I just go out and turn it on 1/2 hour before I use the garage. I have been very happy with it.

If you want to heat it on an occasional basis, forced air electric would be the cheapest first cost.

If you want to heat it 24 X 7, a heat pump solution would be a lot more economical as far as energy usage. Also...although you didn't mention cooling...a/c in the garage is really nice. I don't use my a/c much...but when I've got something I really need to do and it's 90 degrees and 90% humidity...having a/c available is a real lifesaver.

Phil

I agree with Hoosier Buddy. If you want a low cost but effective option consider his suggestion. I have lived in Bloomington, IN and now in Ann Arbor, MI - MI is colder but IN had its share of cold nights. In both places I used (and still use) a 35,000 BTU forced air propane heater (made by Reddy Heater) hooked up to a 20 lb tank. I fire it up and in the dead of winter (freezing temps) I can have a two car garage very comfortable (perhaps 60 degrees) in 10 minutes or so. I also have a portable "Big Buddy" heater (made by Mr. Heater) that runs off of either a small propane tank (about $2.50 from Lowes) or I have a hose and also hook it up to a 20 lb tank. It has a small fan too. Running it after the forced air heater keeps the garage warm for quite awhile. If it's really cold, I have to turn the forced air heater on for a few minutes to warm it back up. It's a crude way to go but it works effectively, is inexpensive, and makes for a usable space. Your insulaton will make a huge difference (both of my garages were insulated, and I insulated my garage door hear with polystyrene in MI). If I had it to do over I might have bought a slightly larger force air heater (maybe 45,000 BTU or more).

A few words of caution. The force air heater does shoot out some hot air - keep an eye on it. It's loud, so while it doesn't bother me to turn it on and work, you can't hear music or the tv over it very well. It's often used on construction sites and they tell you to not use it indoors... for good reason. I've never had an issue and it happens all the time with others. But I suggest that you not turn it on and leave the garage if you might forget about it! The Big Buddy is really quiet.

Good luck.

Thanks for the help guys!

After some further thought and reading these responses, I'm going to probably **** it up and run 220V out there. I would be worried about recovery times with the 110V solutions. I don't want to be heating 24/7 when I'm only planning on doing a couple hours of work a week in the garage.

I am leaning towards 3.) 220V and big ol' electric space heater, as that'll give me an effective solution, but not cost an arm and a leg... and if I decide to put in a heat pump, I'll be able to just tack it on at a later time.

Although I know it's hard to answer without seeing the garage and layout, but how much should I expect to pay for running 220 service approximately 30' from the main (20' in the crawlspace, 10' through pre-existing buried conduit, and another couple feet up to the panel), as well as the cost of a decent 100amp subpanel and installation of maybe a dozen 110 outlets around the shop? The only 220 outlet I'd need for sure would be for the heater, and about 15 feet away from the panel; but I'd probably put in two more just for fun

I plan to put in R-30 or R-38 above the ceiling, and R-13 in the walls (2x4 framing). Will install several soffit vents to keep 'attic' at outside temp. Concrete slab floor, uninsulated as far as I know. Old wooden garage doors are 7x8, probably will be replaced with new R-8 or R-13 doors. One small window (36"x36") and one 30" door will be replaced with low-E vinyls.

Click to expand...

I built my wife a greenhouse/potting shed that is 20x20 x 8' ceilings except it has 2x6 walls. She heats it with 2 of the freestanding oil filled radiators set on the middle setting. Although there is a little humidity in there, it is not over abundant as we just got it finished this fall. She has a few plants in there and it is not a greenhouse as you would imagine. Pics on here somewhere. Anyways...when it got down to 0 degrees outside, her building was 65-70 inside and very comfortable. In the house garage, I purchased a Hamilton LP gas heater that is ceiling mounted and 45,000 BTU. It's not up yet but should easily keep the garage at 75 if I want it to. If you only have a 20x20, I would not go to the trouble of a pellet stove. For one, it will take up too much valuable space and would probably run you out. For that size a 30-45000 BTU ceiling mounted unit would be adequate. Or if you go with something lower than a ceiling mounted unit, add a ceiling fan to circulate air around. Also consider that when you insulate, get a few cans of spray foam insulation and foam all corners and cracks that you see. Then insulate with the highest R-value that you can. Install a vapor barrier over that, then finish the walls off. You'll be surprised as to how easily it will heat.

Kevin

Cost me $600 for an electrician to install the cable, wire in the panels, penetrate the walls, and lay the conduit in the trench I dug. 100A service, aluminum cable (typical for this application). About 60' through the conduit and 30' through the basement. This did not include wiring outlets and lights in the garage. I had to shop around quite a lot to get this price.

Thanks again for the help. I'm contacting electricians this upcoming week to get an idea of what I'm looking at in terms of $$$. Ideally, I'd have them do everything; but moneywise I'm not sure if that's a great plan.