My Garage gets hot in the summer! Outside temp might be 85 degrees Fahrenheit but in the garage it's over 110.
If I leave the door open about 8 inches temperature equals out.

Issues with leaving the door open:

  • Bugs and critters
  • Security
  • Remembering to close it

I've been looking at garage door vents.
enter image description here

  • Crank handles adjustable louvered vents (so I can close the vent in the winter)
  • Rodent / bug screen

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This seems like a good way to keep the door closed and have my ventilation too.

Having the door open allows a lot more air flow than these two vents.
Anyone have experience with these? Do they work?

  • 2
    I'm surprised that leaving the door open slightly helps much. What's your ceiling and roof situation? Roof vents are the most effective means of venting heat.
    – isherwood
    Jul 23, 2019 at 19:00
  • I have a trussed gable roof. There is a vent in the roof. My Garage has a sheet rock ceiling. I have a garage thermometer and an outside thermometer - leaving the door open helps equalize temperature measurably.
    – David D
    Jul 23, 2019 at 19:14
  • 1
    You're basically asking whether vents work. Sure, it'll help, but look at the area covered by those vents vs the area of a gap 8 inches high across your 16-ft door. You'd need more than one. The high-low arrangement is good, though.
    – isherwood
    Jul 23, 2019 at 19:21
  • Recommend putting a full-length ridge vent on your garage roof -- hope you already have soffit vents as well! That setup will provide sufficient area for good airflow. Jul 23, 2019 at 19:49
  • Is your garage door insulated? I had good success adding hard foam board to my south facing uninsulated door
    – Mobius
    Jul 24, 2019 at 16:36

1 Answer 1


I have found vents like the ones you have in the photo to be basically worthless. I have found that a powered temperature activated vent in the roof is almost as good as an air conditioner. The first one I installed was line voltage driven with a temp switch it was really a huge savings in that home, because it dropped the attic temp by 40-50 degrees, the next couple of homes I used solar powered vents, these were a little more up front unless a new circuit was needed and if a new circuit was needed the solar was cheaper. In short a passive ventilation system is limited to the area in square feet you have and the height between them. If I were you I would be looking into a powered vent on the roof, it will work much better in my opinion from actual experience with Louvered vents that were 3’ square compared to a single 8 or 10” powered exhaust that actually cooled the entire house.

  • Are the articles saying don't use attic fans wrong? If so why? energyvanguard.com/blog/75600/… and greenbuildingadvisor.com/question/…
    – David D
    Jul 25, 2019 at 1:36
  • In my case I can say they were 100% wrong a home I had in the 80’s was like an oven no ac except the master bedroom, 1 powered attic vent cooled the attic space enough to eliminate the need for the AC. Was the attic fan pulling conditioned air out of the home ? No the attic with a brown roof was so hot it took until after midnight for that space to cool down then the cycle would start again. Once I added the attic vent the ceilings no longer radiated heat , there was no access to the attic from that wing of the home there was no exchange but the home was much better after the fan addition.
    – Ed Beal
    Jul 25, 2019 at 13:14
  • You can also see in the conversation some disagree I have had houses where it has made a huge difference, my last home had central air I put it in , it was a daylight basement but the upstairs was always much warmer until I added a solar powered vent, my monthly power cost went down and there were hotter months after the install with lower power bills because the system was not having to cool the heat coming from the ceiling (that home had R60 in the attic). I live in Oregon where we only have ~2 months of hot weather it may be different in other zones.
    – Ed Beal
    Jul 25, 2019 at 13:30
  • To echo Ed's remarks, We had a fan put in when we got the new roof. The AC bill this summer was 15% less than prior year, despite average temp these 4 months being same or higher. we had an energy audit, and guys spent a day up there first sealing the whole attic floor, then adding insulation. For a leaky house ceiling, the article may be right. But once properly sealed, the fan works great. Dec 23, 2019 at 13:33

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