I've got a bunch of vents in place: two large gable vents at the front, a ridge vent running across the entire roof, and plenty of soffit vents along the overhangs. My main goal here is to get rid of the hot, stagnant air in the attic, and I'm planning to install a 16-inch attic fan with around 2000 CFM capacity to help with that. The fan will be mounted at the front gable, and I'm using a reinforced flexible duct hose to direct the air to the center of the attic. The real question is whether it's more effective to pull in outside air through the gable vent and exhaust it into the attic, or to suck out the existing hot air from the middle of the attic and vent it outside through the gable vent. What's the better approach?
3 Answers
I agree with the others. Removing air from the attic is the way to go. By doing this, it'll help you draw in cooler air from the outside, which is exactly what you need. Plus, from my experience with a roof ventilator I installed years ago, this method works wonders. It really keeps my house cooler during the hot days.
You should definitely go for pulling the hot air out. That way, you’ll effectively remove the heat that's sitting at the high point in your attic, which is where most of the heat accumulates. By exhausting the hot air, you’ll create a vacuum effect that pulls in fresh air from all your other vents, cooling the attic down faster.
I’ve had a similar setup for a long time, and I've always found that exhausting the hot air makes a huge difference. If you just push air in, you mix everything up, and it takes longer to drop the temperature. Keeping the attic's temps lower can also help prolong the life of your roof.