The whole house fan arrived yesterday from Tamarack industries. We decided to try it out. As you see it here, it is the full open position with fans blowing upward. It's insulated to R38 and will close and seal so you don't have to worry about air leakage when it's closed. It comes with a remote control and has two speeds.
It takes about 15 seconds for the doors to fold out before the fans start. It's a lot quieter than the whole house fans I have had in the past.
We will need to install it before drywall.