Wednesday, September 14, 2011

Cooling it in my garage.

My washer and dryer are out in my garage.

During this recent exceptionally hot spell this Summer, my housekeeper had it pretty rough out there doing my laundry.

The first thing I did was have a 54" ceiling fan installed right above the space in front of the washer and dryer. When blowing down, it simply blew hotter air from near the ceiling down upon her. Reversing the rotation helped a little more but not much.

My next thought was that my north facing, dark colored, aluminum garage door was transferring a lot of heat when it was closed. Of course, it was open when she was here. I Googled "garage door insulation."

It turns out that Owens-Corning makes a garage door insulation kit. You can find them on-line via Home Depot. You will need two kits for a 2 car garage. Cost delivered, about $150.00 for both. Easy to cut and install.  However, do not use the crummy peel and stick tape that comes with it to attach insulation retainers to door. I went to our local Lowe's and bought a cheap caulking gun and a tube of Loctite PL Premium Polyurethane Construction Adhesive. Man, they are on there to stay now! One tube is way more than enough. I have about 2/3 of it left.

I checked my garage temperature against the outside, in-the-shade temperature at 3:00 PM for about a week before I ( well, Sarah and I) installed the insulation. Before, it was 5 degrees cooler in the garage with the door shut. Afterwards, it was 10 to 11 degrees cooler. I'm sure it will keep it warmer in the winter as well.

For a total of less than $160.00 and about two hours of work for an able bodied person, I think it was worth it.

Next, I Googled "attic exhaust fans".  There are numerous ones to choose from. The one I got has the adjustable thermostat on the unit and sits in your garage attic. There are more expensive models that have a wall mounted thermostat and manual control. Mine was about $400.00 with shipping and another $150.00 for electricians to install and wire. Runs on 110 volts. Manufacturer claims that if you ran it continuously, it would be like leaving a 60 watt bulb on all year.

The unit is mounted in the attic through a hole cut into your garage ceiling. It is covered with a grill that comes with it. Looks good. It also comes with two more grills for you garage door. I cut the oblong holes for the grills into the bottom of the garage door (one on each side) myself with a scroller saw and a good metal cutting blade. Piece of cake. Bolted on wit stove bolts. Painted to match door. Looks good.

The idea is that the relatively cooler air (relative to the air in the attic) drawn from  the garage will pressurize the attic and blow the lighter, hotter air out through the ridge vent. Note that with a ridge vent system, if you install a traditional attic vent van through your roof (i.e., the turbine type), all you end up doing is pulling more hot air INTO THE ATTIC.

I've got the thermostat on mine set to the lowest setting, 90degrees. You can set it as high as 140 degrees, but what would be the point? When the air temp in the attic reaches 90 degrees, it stays on and does not turn off (at any start setting) until the air temperature is lowered by at least 20 degrees. I'll have to wait until I get next summer's electric bills to get a feel for how that is working.

Now, tomorrow, I've got a guy coming who will blow insulation in over my garage (none now) and bring it up to R-30 which the rest of the attic is already. Cost for a little over 400 square feet? A measly $200.00!
Had I known that, I would have done it sooner.

I'll let y'all know how that works out.


Garage Equipment said...

Fans are simplest means of cooling garage, and a big one cranking away with the door or windows open cool the space down efficiently.

Jay Moreno said...


My improvments are working quite well. I'm keeping track of temp and elctric bill differences for a full year post installation. I'll let you know.