Attic ventilator fans are an controversial topic. Just so I am sure we are talking about the same thing, these are the fans that mount through your roof to exhaust air from your attic. The reason they are controversial is that they may do more harm than good. The reason for this is that they suck air from the air-conditioned space in the house as well as through the soffit vents to replace the air exhausted out the roof. In addition, the physics of heat transfer in an attic is not what most people think. Heat transfers via convection, conduction, and radiation. Apparently the primary agent for heat transfer to the insulation on your attic floor (and eventually into your air-conditioned space) is radiative transfer from the hot roof sheathing. For this reason, reducing air temperature in the attic has little impact on the air-conditioning requirements for the house.
It is unfortunate that The Villages doesn't use best practices for construction. The best way to handle attics is through spray foam insulation on the underside of the roof sheathing and thereby completely sealing the attic from the outside. With this technique, there is no insulation on the attic floor. The attic becomes semi-conditioned space. I have this in my current home in southeast GA and the temperature in the attic never goes above 85. The sprayfoam insulation on the underside of the roof sheathing prevents the roof sheathing from getting hot and radiating heat to the attic floor. Essentially heat is never let into the attic.
This type of insulation is best applied during construction and retrofitting a new house can be costly, possibly to the point where there is no return on your investment.
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Originally Posted by BCecil
I have a patio villa and I am considering putting in a Solar Attic Fan and/or a Garage Cooling Fan. Has anyone done this? Can you tell the difference? Do you recommend doing this?
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