Where on the roof should a power vent be installed? Where on the roof should multiple power vents be installed if the attic requires two power vents on the same roof?

Power vents should be installed within 3 feet of the ridge of the roof and as close to the center of the roof/attic as possible.

Power vents should be installed within 3 feet of the ridge of the roof and as close to the center of the roof/attic as possible. If a power vent is placed too far down the roof it could leak because the amount of water shedding onto vents increases the further down the roof you go. It could get to a point where the water can start to splash over the stack and into the power vent. If more than one power vent is required to properly ventilate the attic, the power vents should be evenly spaced apart. Be sure that the thermostat/humidistat controls are set the same for each power vent so that they turn on simultaneously. It is critical that there is enough intake ventilation to supply both power vents. For houses where there are two gable ends, two gable-mount power fans could be used if necessary to properly vent the attic. It is very important that the intake ventilation be sized so that there is enough to supply air when both fans are operating at the same time.