I bought a home with a damaged ceiling in the center of the living room. I decided to use some spare parts I had to make a whole house fan instead of repairing the ceiling. I used a 18" round hart and cooley supply register, 2' of straight pipe, 25' X 18" insulated flex duct and a old squirrel cage furnace blower mounted in a steel enclosure. Now, this whole house fan works great and it's quiet. My attic is well ventilated. But I had to restrict the old squirrel cage blower since it isn't designed for the existing static pressure. Its also a pain to seal off when I'm using the A/C or furnace. Total cost on the system was $60 for the 18" flex.
Can anyone recommend where I can find a blower which is designed for the static pressure of about 25' of 18" flex? A insulated damper on or after the blower would then be the icing on the cake.