Will an Attic Fan Blow My Insulation Around?
LESLIE: Now we’re going to take a call from Chris in Ohio who has a question about an attic fan.
Chris, how can we help you?
CHRIS: Yeah, I hope you can help me out today. I have the really loose, the blow-in insulation, up in the attic.
CHRIS: Is all that insulation going to blow around up there? Is it going to get sucked into the motor? What kind of preventive steps should I take to make sure that the fan actually doesn’t get damaged by all this loose insulation that could end up flying around up there?
TOM: Well, when you put the whole-house fan in, did you also install some exhaust ventilation?
CHRIS: Yes. What I did is I did put – I put some soffit vents in.
TOM: OK. Hmm, that may or may not be enough. Here’s what a whole-house fan is. It fits on the upper floor, usually hallway area. It’s a big fan and basically the idea is that when it starts to get a little sticky, you turn the fan on and it just – you open up a few windows around the house and it pulls a nice breeze throughout the house. That air gets pulled up into the attic. You have to install exhaust venting and usually that’s a vent like in the gable wall somewhere; it’s like an oversized attic vent. Soffit vents, OK, but they’re usually fairly small; so I’m just concerned about whether or not you have enough of them.
Now if your question is mostly is the fiberglass blowing around going to be an issue, I would say no because pretty much it settles down. I don’t think it’s going to get too airborne and if it does, it’ll just get blown out the vent.
TOM: Alright? But it’s a better thing to use a whole house fan like that than an attic fan, if you have air conditioning. If you have air conditioning and you use an attic fan, you tend to suck the air conditioning out of the house as well.
CHRIS: We’d only use one or the other.
TOM: Right. Only one or the other. But even if you’re using your air conditioning, you should not use an attic fan; you should just have passive vents. Because the attic fan will suck the air conditioning out of that space.
CHRIS: Sure. And just as a follow-up, if there’s not proper ventilation to the outside with this powerful whole-house fan, what could happen if there’s not proper ventilation for it to exhaust to the outside?
TOM: You’ll pressurize the attic and you won’t pull as much air throughout your house. It just won’t work as efficiently.
CHRIS: OK, it wouldn’t damage the fan itself.
TOM: It would be extreme condition when that would happen.
CHRIS: OK, thank you very much.
TOM: You’re welcome. Thanks so much, Chris, for calling us at 1-888-MONEY-PIT.