Do Solar Powered Attic Vent Fans Really Work?

It’s important that you have plenty of ventilation in your attic to remove hot air in the summer and prevent condensation and moisture problems in the winter. In addition to soffit, gable, and/or ridge vents, you may want to add a power vent fan to your attic to increase air circulation.

Solar powered attic vent fans usually don’t move as many cubic feet of air per minute (CFM) as hardwired fans; but they’re much easier to install, since no wiring is needed. To determine the number of cubic feet per minute needed for a power vent fan, multiply the number of square feet in your attic by 0.7.

Watch this video to find out more.

Further Information

VIDEO TRANSCRIPT

Marcus asks: I want to put in an attic exhaust fan, but I’m not comfortable with running electricity to it. Do you think the solar powered fans are any good?

Danny Lipford: Solar powered exhaust fans have come a long way since they were first introduced a few years ago, and attic ventilation is so important because it can really get hot in any attic space. Now the solar powered exhaust fans are great because all you have to do is cut a hole, put them in place, and you don’t even have to worry about calling the electrician to power any electric motor.

But, the key thing is making sure you size it properly. First thing you need to do is measure the square footage of your attic times point seven will tell you how many cubic feet you need per minute you will need to properly ventilate your attic. Now you might be able to achieve that with one solar powered exhaust fan, but it may take more than that.

Also very important, make sure you have proper intake air. So check out your soffit areas around your overhang to make sure there is plenty of air coming into the attic.

11 COMMENTS

  1. I HAVE VENTS ON 2 OUTSIDE WALL, AT EACH END OF THE HOUSE.
    I HAVE VENTS UNDER THE EVES. AND 4 ROOF VENTS. IS IT TRUE THE THE 2 OUTSIDE VENTS, ON EACH END OF THE HOUSE, COULD HAMPER AIR-FLOW, FROM EVES VENTS AND THE ROOF VENTS ?? IF SO,SHOULD I CLOSE-OFF THOSE OUTSIDE VENTS ON EACH END OF THE HOUSE. OR MAYBE ADD ADD A TEMP-CONTROL EXHAUST FAN, ON ONE END, FOR THOSE HOT DAYS OF SUMMER ? OR NOT WORRY AT ALL ?

    • Hi, Joann,
      Yes, it’s very important to have that introduction of fresh, cooler air into the attic space through the soffit vents for any motorized vent to work.
      Thanks for your question!

  3. Hello:

    I need a second opinion. We have a solar attic fan installed. The motor dies every year. When I called for support they said that the Soffit Vents are killing the motor. They said that if I want to use the Solar Attic Fan I should cover all the Soffit Vents. Is that true?

    I really appreciate you answering the question.

    Best Regards,
    – Subin Shakya

    • Hi, Subin,

      We don’t know all the factors involved since we cannot see your home. However, it’s important to have the introduction of fresh, cooler air into the attic space through the soffit vents for any motorized vent to work.

      Good luck!

  4. I have and area 28′ long x 14′ wide x 12′ tall under my driveway. It is always damp under there. Would a Solar Power Attic fan help with the dampness! if so how much CFM”S would I need. Thank you for your help.

    • Hi, Al!
      We would need more information to understand the situation.
      You say you have an area under your driveway — what kind of area is it?

  5. I have a solar attic fan installed about 7 years ago. Recently it stops and I have to go into the attic (ugh… it’s 90 outside!) and oil and restart it. It goes for awhile and then stops. I know I’m not getting it oiled correctly since I’m spraying from underneath with a silicon spray. I have a small motor oil but don’t know how to use it without all of it coming back down on me or going up on the roof. Should I just get a new motor?

  6. I have an unusual application. I have a seasonal (April-Sept) floating cabin on a lake in NC. It is at most 600 sf ft. We use it on weekends and I have a regular solar system that I use to keep fridge going during the week so we don’t have to drag like mayonaise and hot dogs and stuff back and forth each time we come and go. But it gets very hot in house during the week and makes the fridge die out some weeks when really hot. So I would like to have some sort of separate solar ventilator, maybe down by the fridge compressor like a foundation vent fan to pull the heat out by fridge and maybe enough so it doesn’t shut down when really hot. It is sorta humid too since we are literally floating on water. So less humidity would probably be good as well as it would be nice if cabin wasn’t so hot each time we come. Thanks for any suggestions.

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