Q - I think I need better ventilation in my attic. Is there a problem with using a ridge vent and a power-ventilated fan in my attic?

I figure the more air I can move the better off I will be.

Neal in Lilburn

A - Actually you would think that when it comes to removing hot air from your attic, the more ventilation systems the merrier.

That however, is not the case.

The proper use of a ridge vent system is to have soffit, or overhang vents that allow outside air to enter freely, move up through the rafters, and then move out through the ridge vent.

(When you do this make sure your attic insulation isn’t blocking any of the vents.)

A power-ventilated fan in addition to a ridge vent can end up pulling air back in through the ridge ventand force it out through the fan, basically moving all the air to one small, localized area around the fan. It doesn’t ventilate the entire attic.

It can, at that point, be drawing air in from the outside.

You can use a power fan with gable, canned or soffit vents – or any combination of the four. But don’t use it with a ridge vent.