Got a very hot attic. I have sofit vents, ridge vents and gable vents. Still hot up there. I'm tempted to put in gable fans but I really don't think they help much, they didn't help much in my other house. I think they don't help much because they just mount to the wall behind the gable vent. I did some research and found ventilators for greenhouses. They actually have their own grill assembly that opens when the fan comes on. They also seem to pull more air out than the standard gable fan. So my question is this, would they work in an attic? What problems might I encounter using this type of ventilator?