Do not install any fans until all venting is properly installed. This may take care of the problem and save a lot of money on whole house fan. Grainger catalog use to have a formula that needed to know the cubic feet of house the cubic feet of attic space the vent openings sizes and window and door openings then it would give the size of whole house fan and tell how much more ventilation needed. So seeing all this work and cost just try to vent everything outside and give it a try.
