Attic fans. Does this work?

[rnln]

Do you this thing would work? Thanks.
Active Ventilation 365 CFM White Powder Coated 5 Watt Solar Powered Roof Mounted Exhaust Attic Fan-RBSF-8-WT - The Home Depot

[McLovin]

that thing is pretty small. I can't see it doing much on a house/attic of any real size.

I installed a "whole house fan" in our house years ago. That really works! I can't imagine living without it.

[Scott Douglas]

Just to give you an idea of how much air that moves, the vent fan in my bathroom is rated at 1100 cfm.
That one would put out a very gentle breeze you might not even feel.

[red-beard]

There is no way a 5 Watt Solar panel will move 365cfm.

[Hugh R]

Also without a battery it won't work at night, just after its been sunny and hot outside.

[red-beard]

Get one of these:

Whirlybird 12 in. Weathered Bronze Aluminum Externally Braced Wind Turbine-BEB12WB - The Home Depot

[Crowbob]

When the time comes to replace my ceiling exhaust fan in the main floor bathroom, I am going with as much CFM as is possible. At night, I can open certain windows and completely replace the air in various zones of the house.

An attic fan does the same for an attic. A low output fan, if the operation cost is minimal (such as solar-powered) will be beneficial because it can run full-time in day-light hours.

[LEAKYSEALS951]

I've often thought of placing a whole house fan right above the toilet. Just because!

[rnln]

Thanks guys. I felt that it is too weak too.

McLovin,
What is the "whole house fan"? Is it just named diff, but also mount to the attic vents to pull in and blow out air?
Thanks.

[id10t]

If it is cheap enough, would 2 or 3 or 4 of them work? Even if you hit the hardware cost for a "real" fan, the solar aspect would still save you money.

[Tobra]

Whole house fan is the droid you are looking for, especially if you live anyplace where it cools off at night, like, not Arizona or Texas. It mounts between the ceiling joists and moves a LOT of air. Like you would use if you were painting airplanes in your garage or something.

In Sacramento, there is a nice delta breeze most nights. My parents put one in when they remodeled, and it is shocking how much it reduced their A/C bill. You get up early, open some windows and start the fan. It blows air from the house into the attic. This draws cool air in from the windows you opened, and blows the hot air in the attic out the vents. If it is 60* outside, you can get it to 60* inside in about 5-10 minutes, including the air in the attic. As it warms up during the day, the air in the attic has to warm up quite a bit before it warms up in the house, especially if you have the place insulated.

I was watching their house a few years ago. Went over in the morning, ran the house fan, brought in the paper, closed up the house. Went by in the evening to bring the mail in and move the cars around a little so it looked like someone was home. Thermostat was set to 80* and it was well over a 100* every day they were gone. The air conditioner did not even come on at all most days.

[GH85Carrera]

The whole house attic fan can be great. My parents had on in their house. On the days when it is getting cool in the mornings it is useful. It gets to be a real pain to go to each room with a window and open them all. If you don't like dust it will make you crazy. If you have many allergies it will make you miserable.

[rusnak]

Yup, I installed a whole house fan so that it pulls cool air at night from the side of the house that catches the night time breeze and pulls it through the house, pushing hot air out through the attic vents. It also pulls hot air from the garage if I leave the door open. The intake slats open automatically with air pressure, and then close when the fan is turned off. Pretty slick setup.

[red-beard]

Originally Posted by id10t

If it is cheap enough, would 2 or 3 or 4 of them work? Even if you hit the hardware cost for a "real" fan, the solar aspect would still save you money.

The issue is that the solar panel can in no way give you that much power to run that much fan. When the power is low, the fan will run slower. So they are giving you the full flow rating of the fan, not what you will actually get.

A 1500 CFM fan uses a 1/5 hp motor. With a 1.85 service factor, it will run about 275 Watts (2.5 Amps) @ 110VAC). How is a 5 Watt solar panel going to provide enough power to flow 350 CFM?

The 1000 CFM fan uses a 1/9 hp motor, which would be 153 Watts. A 350 CFM fan will need about 50 Watts to operate. A 5 Watt solar panel isn't going to do it.

[rnln]

Let make sure if my terminologies are correct.

Attic fans: are fans that mount at the vents on the attic (above the ceiling). These fans are pulling in air from the out side at one vent and pushing out air at another vent (all up in the attic). Purpose is to have air movement in the attic (not under the ceiling).

Whole house fans: are fans that mount at the ceiling to pull air from under the ceiling up into the attic. This is the same as bathroom fan.

Did I get it right?

[rusnak]

^ Yes, and another nice thing about the whole house fan is that you don't have to cut a hole in the roof. I think a bathroom fan uses a vent tube that goes through the attic, not into it.

[Scott Douglas]

^ Correct on the bathroom fan.

If your house has gables with vents in them then a whole house fan would push air through those.

[look 171]

Vent your bathroom fan into the attic so the residential vermin will be in for a suffer fest after you relief yourself

[look 171]

Ventamatic Whole House Fan — 30in., 7,800 CFM, Belt-Drive, Model# CX30BD2SPD | Whole House Fans| Northern Tool + Equipment

This sucker is a whole house fan, Ron. It works and will keep temp down a few degrees. I would also recommend you install a power vent on the gable somewhere is possible. Its on a themoswitch you can set up. This way there is air movement to keep the attic cool, thus the temp will be kept under control in the house. The trick is to col the attic.

Hey man, its time to run the AC and keep your beautiful wife happy before she kicks you ass outta the house.

Jeff

[rusnak]

^ That looks a lot like mine. But there is a little pull chain so you can turn it on or off. I have it wired to usually go on with a light switch in the hallway.