[Living a Fantasy]

Looking into a Solar Roof Fan from The Solar Guys to help with my hot attic. Is it worth $900.00? There are mixed reviews on the internet for it. Apparently, it only reduces the attic temperature by 10 - 15%. For my attic would be about 120 degrees with their device. The benefit (from their the marketing brochure) is that it will recirculate air from the outside through the soffets and out the Solar Roof vent.

I already have a fan in my garage and also a passive Dome Vent on my roof. What are your thoughts or experience with dealing with a hot Florida attic?

[JohnN]

I got the electric (not the solar) fan from Solar Guys almost 10 years ago. I think it was $500 at the time. Anyway, I think it does a great job for my garage and the attic. I'm not in the attic much, but when I do go up there, it's not deathly hot by any means. My electric bills runs about $100-$150 a month for 1600 square feet, which I think is reasonable and I think the fan helps there some too. Sure the garage pulls in outside air, but it's shaded and it's fine to work in for whatever time I'm out there as a bonus.

[Toymeister]

I would not get it. Bottom line it will not operate when you need it nor will it reduce the attic temp.

The basis for my statements:

I had an electric fan and a way to monitor it's hours of operation remotely , I'll skip those details for brevity. The fan would often operate past 11 PM to cool the attic. The solar fan will have ceased operation well before that. Solar efficiency is not linear, so the evening hours generate far less electricity than solar noon. You may have a fan running at 1/4 speed at 6PM when you still need 100% speed.

Second, the fan will draw air from all vents, however most will come from the closest vent as air has friction. Visualize where the fan will be installed, at the peak, next to other vents. So the 'vented' air enters at the peak from another peak mounted vent to the solar peak vent. The 'vented' air may travel a few feet. The fan draws little to no air from the hot attic, which is it's purpose.

For these reasons I would not get a solar or 120 volt powered fan. I recommend what I have done and add extra non powered static vents, these will increase your air flow from the soffits to the peak. The standard vents which the builder installed meet code but no more. The code simply does not require much ventilation.

[LateBoomer]

solar powered attic fans work pretty well

[Blueblaze]

I installed one myself in a house I built about 20 years ago that had a hip roof, due to the high attic temps. It was much more powerful than a solar fan, and it helped a bit -- for about two years. That's about how long the fan survived the attic heat it operated in.

I never replaced it, mostly because I realized that if I ever had a fire, a fan drawing the fire up into the attic would likely destroy my house before the fire department ever had a chance to get there.

[Dana1963]

Originally Posted by Living a Fantasy

Looking into a Solar Roof Fan from The Solar Guys to help with my hot attic. Is it worth $900.00? There are mixed reviews on the internet for it. Apparently, it only reduces the attic temperature by 10 - 15%. For my attic would be about 120 degrees with their device. The benefit (from their the marketing brochure) is that it will recirculate air from the outside through the soffets and out the Solar Roof vent.

I already have a fan in my garage and also a passive Dome Vent on my roof. What are your thoughts or experience with dealing with a hot Florida attic?

A little pricey $900 most expensive fan on the internet is less than 350 dollars. There are other companies in the area. A question was asked last week are Villagers being overcharged seems so.
The fans work no noise in the home we have 2 placed about 50 feet apart

[HiHoSteveO]

Post #3 and #6 make more sense to me than spending all that money on a powered attic ventilator.
It is said that when something pulls air from the attic, it must come from somewhere and often that somewhere is the conditioned air inside your home. There are many air leaks into the attic from inside. Attic ventilation is designed to pull air from the soffit vents into the attic and out the ridge vent at the peak of the roof and the static vents placed fairly high in the attic roof.
You might be better served to do some air sealing and add a couple of static vents if you feel that it's necessary (for whatever reason.) but more roof penetrations are not always a good idea.
Here's a quick video... there are loads more on Youtube on this subject.
Don’t Let Your Attic Suck - Power Attic Ventilators Are a Bad Idea - Energy Vanguard