What's the best way to cool a hot(!) garage in Phoenix?

KNS · 07-16-2005, 03:26 PM

A question for those who live in the Southwest, this is a house in Phoenix. The garage is about 600 sqft and gets to about 105 degrees during the day and drops to about 100 in the evening during the summer. Currently there is only one small 8"x14" vent near the ceiling. Horrible. I have thought about venting it similar to the way an attic can be vented with an exhaust fan and additional inlet vents. Or... The house has central air conditioning ducted through the attic. Can an additional duct be brought over to the garage? It won't have an effect on the thermostat in the house and I would only like to see temps brought down to perhaps 90 degrees or so. Any ideas would be great.
Thanks much...

Moneyguy1 · 07-16-2005, 04:41 PM

roll around swamper (evaporative cooler). .

KNS · 07-16-2005, 04:53 PM

Thanks for the reply. I was looking for something that I wouldn't have to think about once installed, like the attic fan idea. Anybody else cool their garage in one way or another?

pwd72s · 07-16-2005, 04:58 PM

I've seen vents with fans that are powered by a solar panel...check with a roofing contractor there.

KNS · 07-16-2005, 05:23 PM

pwd72s,
I've actually looked into the solar powered fans, pretty nice. I don't know how much they'll help. If it's 115 outside, I'll just be bringing in 115 degree air into the garage. Won't I?

BlueSkyJaunte · 07-16-2005, 06:31 PM

You're SOL without a big swamp cooler.

In case you're wondering, I am SOL. Not enough room for a big one and the small ones don't do jack schitt.

88BlueTSiQuest · 07-16-2005, 07:02 PM

A very big window AC unit, a ceiling fan, and a well placed box fan can do wonders. I only run this set up when I'm in the garage, but it does alright as far as cooling the work space that I am in.

I'm running an 18000btu(1.5ton) 220v window unit in my oversized 2 car. Granted, we aren't hitting 105 here yet, but 98 degrees with 85% humidity gives you a heat index of 105 and higher. If I run the A/C 24/7 it'll keep the garage close to 75 degrees, but will run the electric bill through the roof, and that's without an insulated ceiling, 1 uninsulated wall and an uninsulated garage door.

You could likely pick up a unit the size of mine for roughly the cost of a new swamp cooler, so long as you have easy access to a wall you can cut out, and the ability to add a 220v outlet.

Joeaksa · 07-17-2005, 06:53 AM

I have one of these:

Worked very well so far but now that we are close to the Monsoon season, they do not do very well with high humidity.

Found it at a garage sale and paid $275 for it. New price is over $1000 so it was a good buy. Worth every penny and kept us going for months while working on cars in a large warehouse. Now that its in the garage its really overkill but would rather be cooler than not.

Joe A

KNS · 07-17-2005, 10:52 AM

Thanks everyone for your replies. I was also thinking of an attic type fan with a timer. It would turn on late in the evening and run until early AM to help the "cooler" evening temps into the garage and push the hot stuff out the top. 105 I can deal with during the day it would just be nice to see the temps drop in the evening. Sky Harbor had a LOW of 92 degrees the other morning.
Any other ideas... keep 'em coming!

Joeaksa · 12:07 PM

Kurt,

I installed a "whole house" attic fan last year and love it. Run it in the morning until it hits 100, then turn the A/C on. I open windows in the rooms and it sucks cool air from outside through the house, into the attic then out the vents. Cut my cooling costs by 30% and I like it a lot more than A/C.

You could put it on a timer but the problem is that its still over 100 when I hit the sack at 11 PM and too hot for me. In the morning and the 9 months of fall, winter and spring the attic fan is on and doing just fine.

Well worth trying...

Joe A

gassy · 07-17-2005, 12:20 PM

Give my ex a call--she could live in your garage and keep it a frosty 32...

tabs · 07-17-2005, 12:29 PM

Attic/ Whole House fans great ideas...Swamp Coollers another great idea...especially if it has an automatic fill...ANd the only new idea is to INSULATE THE GARAGE DOORS...Mine face South so they pick up a lot of heat...while the garage gets hot the back part of my house hardly ever runs the AC..and stays about 80* all by itself...Trees around the property especiall facing South and West where the afternoon heats things up is also a good idea....anything to shade the houe from the sun....Solar screens another good idea for those windows effected...

KNS · 07-17-2005, 12:45 PM

Guys,
I like the whole house fan idea, makes sense. Joe, I take it each room has a ceiling vent leading into the attic? The fan exhuasts it to the outside/rooftop?
Thanks.

VaSteve · 07-17-2005, 01:21 PM

I just spent the whole weekend sweating in my garage in 100% humidity. Nothing like running that back of your hand across the underside of the carpeting changing the shift bushings. Ug.

Anyhow. Someone once told me that insulating the space above the garage will keep it cool(er) in the summer, and warmer in the winter. I had planned on doing it, but then I remembered how hot it gets on a warm day with a hot engine in there.

Anyone have any advice on this? I have an access hole I cut in the ceiling I need to seal up but would like a denifitive answer before I do...

Joeaksa · 07-17-2005, 01:29 PM

Quote:

Originally posted by KNS
Guys,
I like the whole house fan idea, makes sense. Joe, I take it each room has a ceiling vent leading into the attic? The fan exhuasts it to the outside/rooftop?
Thanks.

Each room does have a vent. Its called a window! I have the fan mounted in a central area of the house and then open selected windows to provide cooling air to that area. No need to open a window in a room where I am not going to use.

Yes, it exhausts the air through the attic then outside. That keeps the roof cooler, which in turn keeps the entire house cooler.

Tabs has a good idea. My garage faces South as well. Problem is that my bedroom is above it. Am going to put a automatic vent fan in there that trips above 130 degrees to cool this are down. Cannot justify running the swamp cooler when I am not in there and a small vent fan will do just fine.

Give my ex a call--she could live in your garage and keep it a frosty 32...

He said he wanted it cold, not frigging fridgid!

JoeA

Moneyguy1 · 07-17-2005, 01:55 PM

Running the cooler when you aren't in an area is no problem if you install three-way switches in two locations. An insulated door will help, but you will still need some ventilation. Your bedroom is right above. So, I assume you mention this because a ceiling exhaust is out of the question. What is wrong with a wall exhaust? Is the floor space between your bedroom floor and the ceiling of the garage insulated? Are the garage walls insulated?

You say 600 square feet and I assume 8 foot ceiling height. That is 4,800 cubic feet of volume. Armed with that number and info on insulation, any A/C dealer worth his salt will be able to size a wall unit for the space, given the amount you want to drop the temp. I would assume that on a 110 degree day, the mid eighties would be your goal.

Racerbvd · Racerbvd's Garage

Quote:

Originally posted by Joeaksa
I have one of these:

Worked very well so far but now that we are close to the Monsoon season, they do not do very well with high humidity.

Found it at a garage sale and paid $275 for it. New price is over $1000 so it was a good buy. Worth every penny and kept us going for months while working on cars in a large warehouse. Now that its in the garage its really overkill but would rather be cooler than not.

Joe A

These are great, one of the teams I crew for has em, when not at the track, they use them at the shop. You also see them on football fields in the south.

David · David's Garage

My garage is almost 1000 sqft. I've got a 2 ton (24,000btu) 220v window A/C unit. It cools pretty well, if I start it on Saturday morning, I can keep it about 77F when the outside temp is 100F. This is in Houston with super high humdity. I would imagine you could get away with a much smaller unit since the humidity is lower, but I'm no HVAC expert.

The only problem I have now is that it's so nice in the garage that I'll hang out, read magazines, check on Pelican, watch TV, etc and not get any work done.

vash · vash's Garage

how much money do you want to spend? vent the attic, with a solar powered unit. and install a ductless AC system in the garage. i think you only need to drill a 3"hole in a wall somewhere. remote control. i may install i triple unit in my house. i bet we could DIY. kinda like installling AC in our cars. (search "duct-less AC" in yahoo)

for the house, have you installed one of those springloaded vents from the house into the attic?

88BlueTSiQuest · 07-18-2005, 03:09 PM

Quote:

Originally posted by vash

for the house, have you installed one of those springloaded vents from the house into the attic?

You sure that's not the 'whole house fan' or attic fan as we call it here? It looks like slotted vents in on the ceiling when the fan is off, but when the fan comes on, the vents open up to allow the fan to suck the air from the house into the attic. These generally work great for areas that don't get a good breeze, and you still like to open the windows.

Our attic fan was removed by a P.O., but I'm not too worried about replacing it, as the humidity here in KS makes opening the windows undesireable.