Figured out I had my attic fan running backward for 3 summers

Was up there last week swapping out a bulb and felt the air moving the wrong way. Looked at the blades and realized they were spinning counterclockwise when they should be clockwise for pulling hot air out. Called my buddy who does HVAC and he confirmed it. So I've been basically pulling outside hot air into the attic instead of venting it. He asked me how long it's been like that and I honestly can't remember. Anyone else ever wired a fan backwards by accident?

2 comments

2 Comments

bethcarr29d ago

Oh man, that's brutal. I did the same thing with a box fan in my garage window a couple years ago. Thought I was blowing hot air out but I was just recycling it back inside. The attic fan thing is even worse because it's so hidden away. At least you caught it eventually, some folks probably never notice.

henryf5329d agoMost Upvoted

actually @bethcarr i gotta push back on this a bit. running the fan backwards isnt always a bad thing if you set it up right. my buddy has his attic fan pulling air from inside his house and it works great for his basement because it pulls cool air up from the basement into the main floor. the trick is making sure you have a path for the air to go in and out, like opening a window in the basement. otherwise yeah you're just recycling hot air like you said.