Solar Powered vents.

JohnnyRotten Registered Users Posts: 1
Hi.....I'm new to the boards and maybe one of you can help me out. My garage is un insulated and my power inverter is in the garage. I have 2 vents in the garage with a id. of 8" x 14". I think I could use 1 ...8" fan or maybe 2 ...7" fans somehow wired together. The vent cover is 10 x 16". I think standard sized vents. My garage gets quite warm and I was wondering if someone out there sells a solar powered fan or dual fan unit that will fit into the opening. Preferably with it's own solar panel that I can mount away from the fan unit on the roof. I have found numerous units that are A/C plugin powered but nothing D/C solar powered. If I purchased 24vdc powered fan or fans how big of a panel would I need to power the fans? And could a 24vdc computer type fan be able to be hooked to a panel directly without any other modifications?? Thanking you all in advance! 8)8)


  • BB.
    BB. Super Moderators, Administrators Posts: 33,406 admin
    Re: Solar Powered vents.

    In general, add insulation to the garage (and shading from trees/trelles, on the outside walls--if possible). And add normal eve and roof type venting (ridge-line, open screened/hooded vents, etc.).

    In general, solar electric fans are on the order of 10-20 watts and move 1/10th the are of a 200+ watt 120 VAC attic fan. Solar fans just do not move very much air and are very costly (at least the well built solar fans are very costly).

    In the past, one poster added solar fans (and more venting) and was very happy with them. A few years later, found that the solar fans had failed, but the attic space was still the same (cooler) temperature as when the fans were operating simply because of the extra added venting.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Solar Powered vents.

    Welcome to the forum.

    This question comes up more often than you might think, as it seems a logical solution. Here's one thread on solar-powered attic venting:

    You have some specific sizing issues which may make it impossible to buy an "off the shelf" unit. I'd go with Bill's advice here and see how much you can improve air circulation without a fan first.

    I have a "cold room" in my carport which has low air intake and two outlets on top. It is fully insulated and hold two freezers. The freezers generate a lot of heat. Most of the time the ventilation alone keeps the room tolerable. But sometimes it gets hot up here. As such I have a plug-in thermostatically controlled fan to keep the air flowing when the temp rises. The difference it makes in terms of freezer run time is worth the money to power the fan as-needed.

    Running small fans ("muffin" or "computer" type) directly from a solar panel is possible, but they don't move much air just as Bill said. You have to look at the fan first and see how much power it requires. In general the Watts will equate to panel size with an allowance for efficient (a panel typically puts out 80% of its rating on average). A 7" DC fan may be pretty tough to find.

    Another thread that may be of use: