I recently received an outrageous electricity bill and decided to invest in an attic fan to help reduce the AC load during the summer. I'm living in an older home from around 1942 that has soffit ventilation, but the insulation is really lacking, especially in the garage attic. While I know upgrading the insulation is important, it's not financially feasible right now. I'm planning to install a solar attic fan to see if it makes any difference. But I'm curious: do attic fans really help with reducing AC strain? I've heard mixed opinions—some say they're bad, some say they're good—but I'm not sure which is true. Additionally, I've been warned that they can cause mold; if so, how exactly does that happen when proper ventilation should prevent it? Any insights would be appreciated!
3 Answers
If your attic temperature is close to the outside air, the fan might not actually help, since it could just end up pulling conditioned air out into the attic. That can make your AC work harder. Also, mold can become a problem if humid air gets pulled in and condenses on cooler surfaces. So, you might face issues if the fan’s just creating more moisture in there.
Honestly, you might want to focus on fixing your insulation and sealing the attic first. That will give you a much better long-term benefit compared to just adding an attic fan. An attic fan might not solve the core problem if your space isn’t really sealed off from the conditioned areas of your home.
That’s a great point. Insulation seems crucial if the fan won't fully isolate the conditioned space from the attic.
Attic fans can help lower attic temperatures, which might help your shingle lifespan and potentially cut cooling costs. But it will depend on how leaky your house is. If your ducts are in the attic, it could help; otherwise, it might not be effective. I have a whole-house fan and it works wonders when it’s cooler outside. Just be careful not to run it when it’s hotter than what you want inside, as that would counteract the AC.
That makes sense! I'll make sure to use it wisely based on the outside temperature.
I get that. It seems the key is controlling airflow properly to avoid pulling humidity in.