Ever insulated a whole-house fan from the top?

[B]

Any experience in cutting the flow of air through the shutter of a whole-house fan (when it's turned off)? I want the solution to be on the top/attic side of the fan.

[Muff]

B, on one of my rental homes I solved the problem by cutting a 1/4 inch piece of plywood the same size as the metal frame of the fan which is mounted in the ceiling in a hallway. I then fastened it with sheetmetal screws to the frame on the hall ceiling, painted it white like the ceiling and it looks great. Then if and when I want to use the fan all I have to do is remove the eight screws and the fan is ready to go. Muff

[Oscar_lives]

What's the "R" value of your 1/4" piece of plywood?

Surely there is a better way to insulate the opening of a whole-house ceiling fan....