Garage cooling

I have an east facing garage and receive full sunlight till late noon. Plus, when there are two cars which have come home with hot engines, doesn't help the already hot garage! I'd always wanted to vent the garage of the hot air and car exhaust fumes for a number of years. Didn't find anything that fit the bill in terms of moving air and being relatively quiet. After installing the fan, it moves a ton of air, cools down the garage by pulling in ambient air - it brings the temperature down to ambient outside temperature & vents out the exhaust fumes from the cars.
Things used:

  1. AC Infinity Shutter exhaust fan
  2. GE ZWave outdoor outlet
  3. Fibaro door/window sensor 2 (with temperature)

I already had the Fibaro door/window as a way to monitor my garage door, so being able to use the temperature readings from the sensor is a plus :slight_smile: (yes, the fan comes with it's intelligent/programmable controller, but that doesn't serve my needs. I use the controller to set the fan speed and that's about it. The controller has power off memory, so when the Zwave plug turns the fan on, it retains the fan speed memory to perform the action). Rule machine takes care of the periodic venting from the garage. It also vents the garage when ever the garage is opened and then closed - the thought is to vent out all the car exhaust from lingering around in the garage! The net result is now the garage is closer to the ambient outside temperature, rather than being an oven!
The AC infinity fans are relatively quiet, and move a ton of air. Check the CFM ratings (Cubic Feet per Minute) before you select a fan. That is the amount of air the fan can move in a minute. That should correspond to the size of the room you are trying to vent and how long you will need to have the fan on, to ensure that all air in the room is vented out. It has metal shutters, which get weighed down in the event of an external wind or rain - keeps rain & bugs out.

3 Likes

I've been looking into doing this. I want to vent up through my attic space which itself is vented. Did you install vents for makeup air in the garage?

Nice solution!

S

Thanks.

Didn't have to add any vents to replace the air pushed out by the fan. There are enough open spaces along the garage door to pull ambient air in. If you want to vent the air up to the attic space, you could use one of their in-line duct fans - something like this - add an intake vent on the ceiling of the garage & vent out to the attic

1 Like

I had this problem with my garage in Scottsdale, AZ (i.e., gets very hot this time of year!). When I moved in, there were two ceiling exhaust fans in the garage, both connected to thermostats. I moved in in June, and I noticed that the garage was super hot,. The dumb builder had it all wrong: putting the fans on a thermostat meant they kicked on when it got hot, but that therefore the air being pulled in to replace the expelled air was even hotter. So they worked as garage heaters.

I yanked out the thermostats and just put in smart switches. Added both inside and outside temperature sensors, and two identical simple rules. If it's cooler outside than in the garage (only true at night this time of year), and the garage is over some temp threshold (for winter), then turn on the fan, otherwise turn it off. This week, with outside temps around 110° F, the fan runs about 11 hours. At start (evening) inside garage temp was 95°, and cooled overnight to 88°. Meanwhile outside temperature sensor hit a high yesterday of 118° (probably with sun hitting the sensor) to an overnight low of 84°.

So, in these extreme circumstances the fan is getting me still 7° of cooling, which I'm happy for. Otherwise, without the fan the garage temperature would probably be about 100° during the day, and cool maybe a couple of degrees overnight.

2 Likes

I've used a couple of different AC Infinity products to create solutions for problems which I didn't know existed, before getting know the fans !!! :laughing:

Nice, I might have to look into this. Last summer (as I am in Winter now in Australia) I installed this and it's already made a difference but if I can have both well even better.

1 Like

I hear you... It is a challenge when the ambient temperatures are as bad as standing in an oven! I'm on the east coast the temperatures are not bad, but having an east facing garage meant that my garage is hot from sunrise till about late afternoon! After installing the fan, I'm noticing the garage @ least 10-15 degrees cooler when the fan has run for about 10-15 minutes :+1:

1 Like

Anything to keep the home comfortable :+1:

2 Likes

Thank god I don't live in AZ. I though it was hot in Houston, TX. I don't think my garage ever gets over 85.

Been running two exhaust fans in our smart home setup over 5 years now, and helps out a lot.

1 Like

Your lucky.

Garage AM6

image

And today is cloudy! Add in the 58% humidity, yeah feels like walking into soup!

Thanks!. My garage door is insulated, and there's not a lot (hardly any) air gappage around the door, even at the floor.

Thanks for the suggestions, I'll have a look at the fans. I think I looked at this line once before, but it's good to hear you're using the product and it's working well!

S

My garage is typically "hotter" than outside in the afternoon, thanks in no small part to the insulated door, and the big windows on the South East side of the garage. Greenhouse effect as it were.

I think if I put the intake vents on the side of the garage that's shaded in the afternoon (e.g. the non cooking side), I could suck in "relatively" cooler air and drop the temp by 5+ degrees.

I've actually thought of doing essentiallly what your builder did but with Hubitat. As long as I keep the fans off in the morning, it seems like I should have an effective cool cycle. There are no windows on the "Morning" side of the garage, so I'm really only fighting the ambient temp here in VA, and the Sun Loading in the afternoon. I think I might spring for Tint on the Garage Windows too to reduce some of the sun loading, but we'll see.

Clearly though, I need to put some temp sensors out in the garage and along the "shady" side of the garage and see what the delta is. I definitely don't want to cut holes in the side of my garage if it won't help! LOL

As a matter of comparison, right now, at 7pm on a thundercloud covered July afternoon, my Garge is 100, and the outdoor temp is 89. Admittedly, neither temp sensor is extremely accurate, but the relative delta feels about right.

If I got anywhere close to the 7 degrees you're getting that would be huge! LOL

Thanks for the illustration of how it works for you. That'll be useful when I get a fan and some vents.

S.

The builder of my home made a second, compounding stupid decision. Since we're in Arizona, we have large air conditioner compressor units, two of which sit just outside the back of our garage. The area is somewhat enclosed, so the heat buildup in that area is high. The vents into the garage were in the back wall, pulling air from this 'heated' area. This just exasperated the problem of the thermostats causing hotter air to be pulled into the garage when the fans ran.

The north side of my garage is open, exposed to just desert. So I did cut two new vent holes in that wall, and covered the two original ones. While the north side gets sun in the morning, it cools off quickly at night. No sooner than I cut those holes could I feel a cool breeze of air coming in. When the fans run, it's pronounced how cool the air is. Since that only happens when it's cooler outside, this works well. My outside temperature sensor is mounted near these vents, while the inside one is mounted on the opposite side of the garage, furthest away from the vents.

Even in your case, be sure the logic of what you have setup only turns on the fan when it's going to pull cooler air in.

2 Likes

Interestingly, that's where I put my two big Air Conditioning units as well...lol
To be fair though, mine isn't enclosed...wide open to the back yard and forest!

Agreed! I've been thinking about this for awhile and haven't pulled the trigger yet. I've got more thinkin' to do, and maybe some data collection. I need to do something though, as I'm putting a freezer out there soon, and as stupid as that sounds...well, let's just say it's put some impetus on solving the overheating problem! LOL

S.

If you're talking about venting into your house attic space you definitely don't want to do that. The only case where that would be acceptable in some states is if your garage is totally finished with appropriate fire rated materials.

No, not doing that! Good Point!

My garage (while attached) has a separate (uninsulated) attic which is not connected to the main house attic at all. It's actively vented (Solar Vent Fan and a Ridge Vent, as well as vented soffets), so pushing air from the Garage into the Garage attic will work, my big issue is just getting "cool" makeup air into the garage when I pull "hot" air out through the ceiling.

S.

I’ve updated the post with a pic of the fan in the garage

1 Like

i live in vegas and would love to replicate this. can you share your code?

What code are you referring to?

Download the Hubitat app