Garage heating and cooling

[Joe R.]

I could use a little advice on heating and air conditioning for my garage. We have moved in recently. The garage is brick, two car, detached. It is not insulated. It has electric service and a garage door (wooden) opener. That's about all it has at present. I am planning to frame the walls and ceiling, add circuits / outlets, insulate, drywall, paint, add lighting and put epoxy on the floor. I would also like to heat and cool it. We live in St. Louis. For those who were here for the convention, you know what summer is like here, hot and muggy! Winter is cold, too, it gets down near zero at least once a year. Any ideas would be appreciated.

Thanks,
Joe

[Grant M.]

Re: Garage heating and cooling

Joe,

There have been a number of threads on garage heating/cooling etc in recent months and even last year or so. Check the archives. John Hinckley was one of the contributors and described his heating/cooling system for the Detroit area of Michigan (not as hot as St Louis in summer, but a bit colder in winter, I think.

For my part, I'd suggest you look at a gas-fired heater if you can get gas easily to the garage (I'm having a Lennox unit installed next Monday--a little late, I guess as we're supposed to get 15 cm--1 foot of snow later today and through this evening). Hydro prices seem to be more volatile sometimes than natural gas, at least they can be up here in Ottawa (Canada) where I live. Insulation's a must, including under the floor to prevent lifting of whatever covering you install. I went the epoxy route that some suggested and self-installed a system by Precision Epoxy from Georgia. Lots of work and somewhat pricey, but it sure doesn't look or feel like paint--even thick paint. It's more like a thick, hard plastic coating.

For cooling, I think John (and others) use an air conditioner that has the compressor etc outside with a single point interior coil and fan unit to distribute the cooled air. Search the archives and I'm sure you'll find lots of good suggestions...

Good luck,

grant

[Charles R.]

Re: Garage heating and cooling

Three words to make your life much more pleasant as you work.. Insulate, Insulate, and Isulate. Don't skimp here at all! If you were building from scratch as I did, Raidant in-floor heat is the only way to go, but since you already have the pad down, either forced air would probably be the easiest. I put a couple of solar powered attic fans in the roof and they really help during the summer! I live in Northern AZ and do not have A/C in the shop, but it never got above 80 inside during this last summer!

Also check out http://www.garagejournal.com/, you will find a lot of good threads on garage and shop info!

Good Luck

[John H.]

Re: Garage heating and cooling

Joe -

I have a 42,000-BTU Mitsubishi "Mr. Slim" mini-split system (cooling only) in my 2600 sq. ft. super-insulated garage, and it has no problem cooling it when it's in the 90's outside; it's also scary-quiet, both inside and out:

http://www.villagephotos.com/pubbrowse.asp?folder_id=1411059

For heat, I have a ceiling-hung Reznor power-vented gas forced-air unit heater with electronic ignition (no pilot flame); it's a 125,000-BTU heater, which turns out to be WAY more than I need due to the effectiveness of the insulation package. I cycle it first thing in the morning in the winter for about 30 minutes to bring the temp up from 55-60 to 75*, then cycle it once every 2-3 hours for about 10 minutes through the day, and it's shut off at 9:00 PM. It gets COLD here in the winter, but the garage has never been below 50*, even when we've been gone for a week with the heat shut off and outside temps in the single digits.

Spend the money first on the best insulation package you can afford - it makes ALL the difference.

[Stuart F.]

Re: Garage heating and cooling

Do we all put Performance Parts Vendor stickers on our tool boxes?

Nice looking garage John. Wish mine was that clean.

Stu Fox

[Paul J.]

Re: Garage heating and cooling

Joe:

As previously suggested, you need to insulate the garage. R-13 kraft-faced batts should be sufficient for the walls, but you could go to R-15 unfaced with polyethylene sheeting over it if you think it's it's worth it. You need at least R-30 in the ceiling but I usually go with R-41+ for the extra heat retention. Do not use a vapor barrier in the ceiling because it will cause condensation. I use steel garage doors with foam insulation on the back, and install gaskets around them. The greatest source of heat loss is from infiltration. For gaskets I use the plastic flap type trim material meant to seal the sides and top of garage doors. Your floor might already be insulated depending upon the age of your house and your local code, but it probably isn't. This is not as big a deal as you might think. Your ground temperature under the garage is higher than it is under unprotected ground and should be around 50-55 degrees. The slab will also act as a heat sink and absorb heat if you heat the garage. Concrete always feels cool because anything that's not warmer than body temperature will be cold to us. Don't forget your windows and access door. These should be insulated items also.

As far as humidity, seal your garage floor. You can use epoxys but they're expensive and you'll still have the possibility of lift even if you etch the heck out of the floor. I've used the water based sealers from the home center with great success. I've not had problems with lift and the humidity levels stay down in the shop. It takes at least 3 good coats.

If you have any brick or block revealed (from the inside) at the foundation, seal it with two coats of Dry-lock, and caulk or otherwise fill any holes.

My house came with an uninsulated/unheated garage, and I watched my beloved tools rust. I do not heat my shop, but I took the measures above when I built it and I've pretty much eliminated my rust problems.

I wish John hadn't posted the picture of his heater. Now I'm envious.

Paul

[Tom M.]

Re: Garage heating and cooling

I have a 30,000 BTU unit,45,000 unit would be better i think, 500 sq ft garage that i heat,
insulated walls, ceiling

[Tom M.]

Re: Garage heating and cooling

UNIT PICTURE, MOUNTED ON CEILING, POWER VENT,30,000 BTU

WORKS GOOD

Tom

[Roger S.]

Re: Garage heating and cooling

My garage is 31' x 28'. Central Virginia is hot and humid in the summer and it does get to zero at times during the winter. My garage is a garage, it houses my 1973 Corvette and my son's '07 Mustang GT. For cooling I just have a single 10,000 Btu window unit. As a rule of thumb 12,000 Btu's will cool 600 sq ft of living space. When I turned the A/C unit on it took about 1 hour to take the heat out of the garage and another two hours to cool the garage to t-shirt temps. For heat, when I want it, I use a 23,000 Btu kerosene heater. I takes about a hour to warm the garage up to long sleeve work temps and in about 2 hours I am working in my t-shirt. By mid afternoon I turn the heater off and work until bedtime. The walls are insulated and the doors are metal with foam insulation and the doors are sealed to the walls with the rubber overlap strips.

Roger

[Martin N.]

Re: Garage heating and cooling

Up here in Northern Illinois we use Radiant floor heat and a VERY slow ceiling fan to move the air around. Here's the 74 in rest for the winter.

Marty

[David T.]

Re: Garage heating and cooling

After 25 years of having my tools stick to my hands in the cold. I installed a Hot-Dawg Heater by Modine. I can't believe the difference! Now I can work out there during the Michigan winter in a tee shirt. Should have done it years ago.

http://hot-dawg.modine.com/

[Martin N.]

Re: Garage heating and cooling

HEY DAVE-

You got shorts to go along with the Tee shirt?

Marty

[David T.]

Re: Garage heating and cooling

No shorts, Marty! They just don't have that 'Fonzie cool.' That is if Fonzie was were in his 60's. Come to think of it he is! Gotta do brakes on my kid's SUV tomorrow so the Hot Dawg will get cranked up. (No sandals in the garage either!)

Dave T.

[Tom R.]

Re: Garage heating and cooling

I would like to see some close ups of how some of you have sealed the garage doors with flaps and things described.

[Wayne P.]

Re: Garage heating and cooling

May not be the most energy efficient in your area, but the small thru the wall heat pumps like motels use work well for a small garage.