Trapped air and heat in the attic may cause problems for some roofing materials. It could also cause condensation and cause mold problems. This is why attic spaces must have ventilation integrated into the structure. Ventilation openings are placed along the areas of the lower eaves and on the upper ridge of the roof or at the end of the gable.
These openings allow cooler, cooler outdoor air to circulate naturally by convection upward from the eaves and out through gable vents or ridges. An attic fan will always be less visually intrusive than a whole-house fan because it doesn't have any openings to the living room. If the attic fan is located behind the house's existing gable vent (instead of a shutter-type fan to replace the vent), the fan will be almost invisible from the outside. Usually, the highest point is the roof of the upper floor, so the obvious route for air is at least to the attic.
As long as the attic has electrical power, the most difficult part of installing a fan for the entire house is cutting the drywall from the ceiling and attaching the damper box to the ceiling beams. Your plan will likely require a fully sealed roof, a very thick layer of insulation, radiant barriers (layers of reflective sheeting) above the insulation (preferably between the beams) to block radiation and insulate the warm attic from the cold house, additional ventilation openings, and possibly an electric attic fan to remove hot air from the attic at the appropriate exchange rate. One of the most common reasons for a poor experience with attic fans is poor installations that cause leaks and roof damage. However, the fans in the whole house are designed to withstand large amounts of air, so it's better to ventilate the fan in the attic rather than directly through a huge vent in the ceiling or in the gables.
A whole-house fan is located inside the attic, but it must open up to the roof of the house, with a ventilation hole covering the opening. However, a house with adequate insulation (at least in non-tropical climates) will have enough insulation between the roof of the top floor and the attic itself so that the temperature of the attic doesn't matter too much; the heat won't have much effect on the floors below. One of the main advantages of attic fans is that they help maintain the integrity of asphalt roof tiles to delay deterioration and prevent them from deforming. They won't make the roof last forever, but attic fans can reduce wear and tear, improve years of roof use and delay costly ones replacement costs.
I have a crested ventilation grille and ventilation grilles on the edge of the roof, because the contractor forgot to place soffett-type ventilation grilles in the house. An attic fan actively improves attic ventilation, saving money on energy bills during the summer and helping to preserve the integrity of the roof; it seems to be a good choice for those who have ventilation problems in the attic. The installation of an attic fan that is most visually annoying will be one where there are several fans on the roof. A warm attic radiates heat through the ceiling, just like the heat of a coffee cup when you hold it with your hand.
A fan located centrally in the ceiling of the upper floor can change the air in the house three to six times per hour, depending on the size of the house and the capacity of the fan.
