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MWS · 10-21-2018, 08:42 PM

Before we built our addition and dream garage, we had small garage (apx 400sf) with no insulation (open stud cavities, no drywall)...here are a few tips:

-If you have open stud cavities, insulate them. It's cheap, easy and has big benefits.
-If you have an uninsulated garage door, use sheets of rigid foam insulation (1" or 2", whatever fits) and can be installed with a couple of dabs of construction adhesive.
-Also regarding garage door, adjust rollers (or shim if needed) so door fits tight to wall...also check door weather stripping (I found gap around door the biggest issue for heat loss).
-Heating...I never found any 120V heater that I liked...tried ceramic, oil filled radiator, etc...the only option that really worked was either propane or kerosene...but make sure you are ventilated. What I found was using kerosene heater to heat space, then shut off and open door for a few seconds...the "stuff" in garage (and cement floor) worked well as a heat-sink and even after door was opened, a small electric heater kept temps ok (or at least for a while).
-Ceiling fan...I know this sounds counterintuitive, but since heat ends up at the ceiling I found that a ceiling fan really helped keep temps more uniform. Fans are cheap (under $50), pretty simple to install (especially if you have a door opener...just run a wire from opener outlet to another well secured box, and mount fan).
-If you have a concrete floor, any thermal break will be helpful. I bought a roll of "outdoor carpet" for cheap and was amazed at how much it helped.

If you are looking for a long term solution, you should look at either a natural gas hanging unit or a 220 electric. If you are wondering what we ended up doing, our old furnace wasn't sized for our house with addition, so it went to the garage. As an added benefit, we also moved the coil and compressor giving us A/C as well as heat...

EDIT:
Before you buy anything, do some math. Get an estimate of the volume of the space and google the BTU's needed for reaching (and maintaining) your target temp. Also, many electric heaters don't list BTU (just watts), but again google watt to BTU. Another tip is to measure your thermal drop...on a night were temps are projected to stabilize, put a thermometer in (warm-ish) garage and check in the morning...divide degrees by hours and you'll see how much make-up heat is required per hour. Also check the amps that you have available in your garage...two heaters might sound good, but you might exceed your amp draw. Lastly, it's easier to MAINTAIN a temp than trying to REACH a temp, so always keep garage somewhat warm....as I mentioned earlier, you aren't just trying to warm the air, you'll have a huge chunk of metal (your car) acting as a heat-sink; trying to raise the temp a couple degrees is better than dozens.

Best wishes, and sorry for the length.

10-21-2018, 08:42 PM	#10
MWS Registered User Join Date: May 2016 Location: Northern Indiana Posts: 410	Before we built our addition and dream garage, we had small garage (apx 400sf) with no insulation (open stud cavities, no drywall)...here are a few tips: -If you have open stud cavities, insulate them. It's cheap, easy and has big benefits. -If you have an uninsulated garage door, use sheets of rigid foam insulation (1" or 2", whatever fits) and can be installed with a couple of dabs of construction adhesive. -Also regarding garage door, adjust rollers (or shim if needed) so door fits tight to wall...also check door weather stripping (I found gap around door the biggest issue for heat loss). -Heating...I never found any 120V heater that I liked...tried ceramic, oil filled radiator, etc...the only option that really worked was either propane or kerosene...but make sure you are ventilated. What I found was using kerosene heater to heat space, then shut off and open door for a few seconds...the "stuff" in garage (and cement floor) worked well as a heat-sink and even after door was opened, a small electric heater kept temps ok (or at least for a while). -Ceiling fan...I know this sounds counterintuitive, but since heat ends up at the ceiling I found that a ceiling fan really helped keep temps more uniform. Fans are cheap (under $50), pretty simple to install (especially if you have a door opener...just run a wire from opener outlet to another well secured box, and mount fan). -If you have a concrete floor, any thermal break will be helpful. I bought a roll of "outdoor carpet" for cheap and was amazed at how much it helped. If you are looking for a long term solution, you should look at either a natural gas hanging unit or a 220 electric. If you are wondering what we ended up doing, our old furnace wasn't sized for our house with addition, so it went to the garage. As an added benefit, we also moved the coil and compressor giving us A/C as well as heat... EDIT: Before you buy anything, do some math. Get an estimate of the volume of the space and google the BTU's needed for reaching (and maintaining) your target temp. Also, many electric heaters don't list BTU (just watts), but again google watt to BTU. Another tip is to measure your thermal drop...on a night were temps are projected to stabilize, put a thermometer in (warm-ish) garage and check in the morning...divide degrees by hours and you'll see how much make-up heat is required per hour. Also check the amps that you have available in your garage...two heaters might sound good, but you might exceed your amp draw. Lastly, it's easier to MAINTAIN a temp than trying to REACH a temp, so always keep garage somewhat warm....as I mentioned earlier, you aren't just trying to warm the air, you'll have a huge chunk of metal (your car) acting as a heat-sink; trying to raise the temp a couple degrees is better than dozens. Best wishes, and sorry for the length. Last edited by MWS; 10-21-2018 at 09:26 PM.