How to heat a 2-car garage shop

[Chris Atzinger]

Hi,

My shop is in an attached, 2-car garage, about 20'x20', with a single double wide overhead door, and 1 entrance to my house.The ceilings are 8' in most places, and 9' near the door.I am a bit of a tool/wood hoarder so space is at a premium. The garage is not really heated, and it's getting pretty cold. Right now, I am using small electric heaters, or occasionally, a propane heater, neither of these are great long term solutions.

How are you guys heating your shops? Anything you would do differently? what would you recommend?

Thanks!
Chris

[Tom Ewell]

My shop is conditioned already but auto repair needs are cropping up and need to use the unconditioned garage area. Have yet to hook up mine so can't comment on actual performance but depending on available circuits, you might check out electric garage heaters as potential solution.

My intended use is just to make the garage 'workable' as need arises but adding insulation and wall finish might make for a more seasonal heater for shop use.

[Art Mann]

I use a 240VAC, 18A space heater in a free standing shop that is 24 X 28 and it works just fine. Resistance heating is expensive though. If I had it to do over, I would probably either use a vented natural gas heater or better yet, install a mini split heat pump.

Please provide a little more information for the community to help you better. How much do you want to spend? Is the house wiring such that you can easily pull a 240VAC wire to run a heat pump or higher power electric heater? Can you install a unit through a wall or window opening? Are you willing to put up with a forced air "torpedo" style propane or kerosene heater? Do you also want air conditioning in the summer?

[Don Nicholas]

My shop is just under 1000 Sq Ft with 8ft Walls. I searched out a used electric furnace from a mobile home for $25. It requires 220 volt and the unit works just fine. Hopes this helps.

[Kent Smith]

The more insulation you can install in the walls and ceilings the less $ you'll spend on whatever heat source you pick. Extra weather-stripping around the overhead door plus rigid insulation installed in the door (unless it's already insulated) will make a huge difference in keeping heat in and cold out.

[Jim Andrew]

I live in the county so space is not an issue, so I have an outside wood heater, as I am concerned about having a fire in my woodshop. Since I built mine, have found some reasonably priced manufactured units. What I did was build a 6x6 steel building a few feet from my shop, and ran 2 ducts between the building and the shop. Found the return had to be attached to the blower motor on the furnace to work properly, or the blower would suck smoke from the firebox, and after all the work, found that buying a manufactured unit in the 2 to 3 thousand dollar range would be reasonable. We are having a real winter storm here, and the heater is keeping up with the need.

[Chris Atzinger]

Hi Guys,

Thanks for the responses. Just a few clarifications:

-The garage is insulated and has finished drywall. Two walls are interior, 1 exterior (plus the door). There is a bedroom over the garage, so I think the insulation is OK.
-I have 220 electric already, and could run another 50A line out there if necessary. I also have a natural gas line, which I could tap into (i am not sure about building codes, though).
-It doesn't need to be heated 24/7, only when I am out there.
-Cost is always a concern, but I want to do it right, as I am going to be in this house for another 10 yrs at least ( or so I am told!)

Thanks!
Chris

[Keith Outten]

Chris,

I was using a 220 volt heater I purchased from Lowe's until last Summer which did a great job of heating my 24 by 36 foot shop with 9 foot ceilings. I decided I needed to improve my air conditioning for the Summer months now that I am working in my shop full time again so I had a Mitsubishi Mini-Split heat pump installed.

Although the mini-split unit was expensive it is worth every penny and my operating costs are much lower than the electric heater. Whisper quiet and a perfect 70 degrees F in every square foot of my shop space. No ductwork to deal with and no cold air blast like traditional heat pumps. The mini-split doesn't need auxiliary heaters so a 220 volt 20 amp circuit is all that is required for power.

Should the need ever arise I could easily move the mini-split to another building or sell it when the time comes to shut down my shop. The only thing I would have to do is plug a 4" hole in the wall.

[Ole Anderson]

45,000 btu ceiling mount natural gas unit heater.

[Dave Kirby]

How do you keep the cast iron tables in your garage shop from sweating and rusting when the temperature changes from heating and then cooling back down. Is there a way to avoid this other than keeping the garage at a constant heated temp? (which I imagine could get expensive unless it's thoroughly insulated.)

[Randy Gazda]

45,000 btu ceiling mount natural gas unit heater.

ditto

I put in a Big Maxx by Mr. Heater last year in a very similar garage, it worked great. Did all the work myself except the NG hookup (which the plumber did without shutting off the gas!). If you buy the heater, don't buy the install kit, is cheaper to buy the parts and pieces you need at Home Depot. I put programmable thermostat but probably wouldn't need to do that.

Cost about $750 when all said and done

[Mike Cutler]

If you have NG to the house, put in a NG powered heating unit. With that bedroom over the garage make sure it vents through the wall and you meet all of the air in leakage requirements, or it takes in air from outside. You're garage is only 400 sq/ft. so you won't need a big unit. There are some nice single source wall units that sit between stud bays. Very easy to install.
That bedroom above makes it a little more complicated, and has to be your first priority in choosing a system. It's not just as simple as throwing a unit in to heat a space. Whatever you get, it needs to vent outside.
You may also have to re-sheetrock the ceiling unless you already have the adequate fire rated drywall on the ceilings and walls. Just something to consider.

[Art Mann]

I agree with Mike Cutler unless you also want air conditioning. I expect that would be your cheapest option from a fuel cost perspective.

[Dave Lash]

A friend of mine sucessfully heats his two car attached garage with a 240 volt Fahrenheat electric heater, he is located near Canton Ohio. Before installing the heater, we blew in fibergalss insulation in all outside walls and the ceiling. We also installed 1 1/2 foam insulation on the garage door. The added insulation keeps the garage warmer all winter even when the heater isn't running just from the heat loss from the house, and it is easier to raise the temperature in a 45 degree garage than one at 30 degrees.

[Chris Atzinger]

Just out of curiosity, what's the avg cost of a split heat pump? I have not considered those before.

Thanks!
Chris