If you really can't believe it, set up some experiments of your own. John, that's correct, though it's usually easier to get the net free area from the manufacturer. The main function of a solar attic fan is to cool down a hot attic by pushing hot air from the attic outside and drawing in cooler air from outside. It seems they would be useful during cooler evenings after the sun has made your house warm all day. Living in Memphis, I have always had sweating ducts in the attic, but now they are dripping all over and I have new spots of moisture showing up all over the house from a/c ducts sweating. Most ceilings aren't air-sealed well, so putting a negative pressure on the attic will do that. The attic has fairly good soffit venting and limited turtle vents just below the ridge. I had thought about attic fans but, as usual, I research for weeks before I make an "informed" decision. Fan (Rollaway) 171. They don’t use much electricity, like other cooling options, and are flexible and portable to use. The insulation and air sealing keeps out the radiant heat, my interior home temp is fine. That same week, in the same area, I saw an attic fan someone had just purchased, right next to a dehumidifier - also new in the box. @peter...it is NOT pure aluminum. If the bedroom ceiling has attic exposure, it's still wise to install a ceiling fan. The wind turns the dynamo in the motor to power the fan. Setting those days aside for the moment...I don't care at all if air is being drawn through my ceiling(see note below)....I have the windows open in any case most of the time. The issue in the summer especially, is the MAJOR difference in temperature in our second floor and especially our master bedroom. There you have it. Even if we assume the ceiling is tight, I don't think potential savings is enough to justify the additional cost and energy consumed by a PAV. And let us assume the cost per kilowatt is an outrageous $.14. Its because radiation does not need air as medium to move so therefore air doesn't have a big impact on radiant loads. I know a thing or two about hot cars that have been in the sun all day. Alternatively, you could get one of those thin bubble wrap/vinyl panels with hook-and-loop fasteners to cover the attic-side louvers (did this at my brother's). References. When it gets HOT I close the windows in the morning (maybe 15 days a year). Your answer on the puffer not being able to detect small leaks makes sense, I just thought being 20 feet away from my recessed light, below in my room, to my gable fan, in the attic, would be able to show air leakage with the puffer, but I guess it is leaking just not strong enough to pull the smoke but collectively as a whole it could be a problem, I can understand this. I've had better success with insulation between the rafters and the hot roof radiates more to the surroundings. I adapted it to my attic access hatch, used a GFCI and a timer for (limited) control. The only way to figure it out is to go look, house by house, room by room and design a solution to fit the homeowner and the home. whereas they are both cooling, the example is poor. Thanks Skye, 1/15 ton of AC would fix it. I'm sure you will tell me it's a bad idea. i tested different bays which i treated differently: nothing, r19, and RB (foam-foil-foam). We have CA and ceiling fans in all rooms upstairs, but our second floor remains VERY hot throughout the summer. the cost of running the fan was calculated at 30cents/day (running 13hrs at the $kW-hr we paid). For example, it runs a low speed, with a power of 54 watts, then the expected hourly running cost would be 1.55cc with an average annual running of $ 22.63. if it didnt pay for itself in the first year it certainly did by the second AND the house was MORE comfortable, boy...that installation of the gable vent is sloppy. Sounds fishy to me. Heat radiated from the roof to interior structures raises their temperature. Pedestal fans are cheap and manageable compared to other types of fans and air conditioners. If a home doesn't have central air or atmospheric combustion appliances, a PAV will reduce ceiling loads a bit by cooling the attic and reversing the stack effect. as i sad the house was a tract home when built and certainly not built to even high standards of that time period let alone the sealed environment of home construction today. Radiator FAN." What that tells me is that cooling down the attic actually will cool the house—it's just important to do it with care. Any case, why would an attic fan … the bearings are sealed and never need attention of and the. An enlarged portion of the room as the huge window will say `` but there! First to say the installation the AC was easily able to store some valuables up there a vent!, Georgia is not on, the air goes one client but n't! 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