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Need To Purchase Attic Fan That Is On Our Roof - Wondering If Anyone Has Ever Used A Solar Powered One..........considering It And Wondering If It Is A Good Idea?
Interesting product. I think I would be concerned about a couple things:
1. no adjustable thermostat - set to go on at 80 and goes off at 70. Not sure where you are located, but here in East TN, the fan would be running from May to November. Most of the thermostat fans I have seen have settings a little higher. A 100 degree attic is not that uncommon in the summer.
2. kind of high cost at $375.
3. They show installation with only 50 year caulking. I bet when storms bow in, you might find a bunch of them in front yards.
The only advantage I see is that they don't use electricity.
I'm curious about the attic fan question. I was told by a few roofers that the attic fan isn't really necessary any more on most homes as the new roofs have roof-vents and most have cross ventilation from vents on either side of the home plus in the eaves. I also have been told (and have lived this) that the fans require replacing every 4 yrs as they seem to freeze up.. no matter how good of one you get. Don't mean to hijack this thread, but I wonder.. is this all true?
Seems to me like money would be better spent insulating the area between the attic and the living/climate controlled area...this way you would get the benefit of keeping out the undesirable temperatures (hot in summer, cold in winter) all year round...also, I would make sure attic ventilation is correct as is so you can get the "passive" ventilating system up to par.
I installed one in my brother's home 7 years ago and it made a 10 to 15 degree difference in attic temperature...
He took it out when he re-roofed with a continuous ridge vent which seems to work fairly well.
The fire chief in his city now requires a high temp cut-out switch so the fan will NOT work during a fire... I guess there have been several cases of fanning the flames...
I installed one in my brother's home 7 years ago and it made a 10 to 15 degree difference in attic temperature...
He took it out when he re-roofed with a continuous ridge vent which seems to work fairly well.
The fire chief in his city now requires a high temp cut-out switch so the fan will NOT work during a fire... I guess there have been several cases of fanning the flames...
I think that temperature drop is due to the fan running when ambient temperatures are low.
Attic fans set to run when the attic is hot are trying to lower the temperature during the hottest part of the day, when replacement air is at its high temperature.
It would appear that running the fan at night, and early morning when replacement air is coolest would help reduce the temperature in the attic more efficiently.
And maybe the 80 degree upper limit cut-off mentioned by a PP would satisfy the fire chief.
OK, I'll give you permission....go ahead and buy it.
Ventilation is very important. The fan is needed. You must have thought it was a good idea or you wouldn't have considered it. So go ahead, make the plunge and buy one.
Seems to me like money would be better spent insulating the area between the attic and the living/climate controlled area...this way you would get the benefit of keeping out the undesirable temperatures (hot in summer, cold in winter) all year round...also, I would make sure attic ventilation is correct as is so you can get the "passive" ventilating system up to par.
Insulation is a given, but better ventilation will help R value do it's best work. 140+ degree attics in summertime are alot to overcome. I think it would depend on how much space you're using of that roof (knee wall of a gable, full attic unused except for storage etc) and how well you've managed thermal bridging.
Granny's old house had a beastly mechanical fan (electric) that made a racket and would suck the toupee off a mans head with vaccum pressure in the house, but the house did cool down considerably. (well, maybe I'm exagerating a tad about toupees ). The problem with her system, if I recall, was that she didn't have a big enough suction end on the other side of the attic, which made it prone to grabbing air from inside the house instead of restricting it to the attic. The attic door plate in the ceiling would whistle.
Passive ridge vents can only do so much. If that's enough to offset extreme temps after insulation, ok. Living south, I would think it wouldn't be enough.
I think the OP should ask the same question in the garden forum for people with greenhouses, because they're likely to have the most direct knowledge and use of them. I like the idea, but like ultrarunner mentioned, there are unforeseen consequences with any new application. Gasket life can be an easy adjustment if that's what's holding you back.
Need To Purchase Attic Fan That Is On Our Roof - Wondering If Anyone Has Ever Used A Solar Powered One..........considering It And Wondering If It Is A Good Idea?
Yes. They are a great idea! If you have a solar attic fan with a rated flow rate in CFM = (attic volume x 10)/60 it will greatly increase the efficiency of your AC Unit(s) in the summer.
They are also useful in the winter if you get ice dams on your eaves.
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Though What Are The Suggestions To Do: A Solar Powered Fan Or An Electric Powered Fan?
). The problem with her system, if I recall, was that she didn't have a big enough suction end on the other side of the attic, which made it prone to grabbing air from inside the house instead of restricting it to the attic. The attic door plate in the ceiling would whistle.
