OK, the insulation sounds like a type of "rock-wool".
Exhaust fans from resi bathrooms have been required to be vented outside around here as long as I can remember; and kitchen range hoods also.
Gut feeling is all exhaust fans should be properly vented to the exterior, with APPROVED ducting and caps.
Again, I think that what you are calling a 'whole house fan', and what I call a 'whole house fan' are two different animals. The attic ventilator fans, if properly sized will provide proper ventilation for the attic, IF adequate make-up air (intake) is available.
John
