Solar Attic Fan DIY

I bought a 12V portable fan from Walmart for $10, removed the case, and mounted into a piece of plywood. It was then put into the gable end vent, and connected to a 15 Watt Harbor Freight solar panel. No regulator or timer needed. When the sun is up, the fan is running. This video was taken about 5 PM, and the fan has already slowed down some. During the peak of the day, it moves a fair amount of air. Also shown in the video is the powered vent fan (120VAC) that was replaced by my inexpensive solar setup.

Category:

Education

Tags:

• DIY
• solar
• attic
• fan
• gable
• vent
• harbor
• freight
• 15
• watt

[01Commenter10]

and wether or not its moving enough air to even make a difference, guess the real way it to mount a thermometer up there and leave the fan off for a few days to soak up the heat, then record the temp, then kick the fan on for a few days and see if the temp drops any…...

[2manytoyz123]

@01Commenter10

I've actually put a Hobo temperature monitor in the attic. Problem is, the weather changes enough day/day to skew the results. Can't get consistent days with fan off all week, or fan on all week. FL weather is almost always changing. Hot & sunny, hot & cloudy, raining, cloudy, sunny, could all happen in a single day. Bottom line, the attic is STILL too hot. Needs more airflow.

[01Commenter10]

The real question is, does it pull out enough heat from the attic so that the a/c does not have to work as hard..??

[2manytoyz123]

@01Commenter10

I wish I could say it does without hesitation, but honestly I can't. It IS moving hot air out of the attic, and when standing on the roof, it feels like a significant amount coming out of the vent. However, my attic is still almost as hot (a degree or two cooler), so it's not effective enough. I will put a gable end vent on the other end of the house, and see if the cross ventilation helps.

[01Commenter10]

@2manytoyz123 yea, what i was told by some roof companies and home depot was that you need to place 2 fans in the attic, one fan on one side to pull in cooler air from outside and the second fan on the other end of the attic to push the hot air out of the attic… this way there are 2 fans working to help remove the hot air…

I have never spoke to anyone that has this setup so i cannot comment on it… Most only have that one fan like yours is but i guess its how much air that fan is moving

[2manytoyz123]

@01Commenter10

I believe it. Even with the fan running full speed, move back a few feet inside the attic, there's no airflow I can actually feel. The vinyl soffets have tiny slits, and the ridge vent is completely ineffective. Just dead air in the attic. Until I put in another gable end vent to allow airflow into the attic at the other end, a fan at one end just doesn't do it. Might try the push/pull idea, thanks.

[SuperDesi45]

Do I need Battery for this?

[01Commenter10]

@2manytoyz123 yea i think the push pull is the only way it will work cause like u said, you went back a few feet and didnt feel any air movement which means that fan is only moving so much air in that immediate area… which does no good for the rest of the attic, So maybe stronger fans and the push pull configuration may be the only option to effectively drop the temps down to make a difference…

[2manytoyz123]

@mao2878

The brand is Ozark Trail, sold in the Walmart camping section. Presently about $12.

[mao2878]

what kind of fan did you buy? i got a 15 watt 12 volt panel from habor freight.