Originally Posted by
Daniel Palm
I installed a powered gable vent in my attic. It is an exhaust vent. Would it be bad to make it an intake vent?
Daniel,
As currently installed, that powered gable vent is depressurizing the attic, doing all the wrong things to the house area: pulling out conditioned air which you paid to condition and putting it into the attic; pulling out extra moisture from the house and putting it into the attic' depressurizing the house in the course of the preceding which then brings in more air from outside which needs to be conditioned; bringing in moisture and contaminants (allergens if you are a family member has allergies) from the outdoors; potentially pulling garage air through the house - if the house walls/ceiling leak more than the garage walls/ceiling does; just not much good comes from it.
Turning it around backward and making it into an intake would pressurize the attic and cause basically the same thing, only in reverse: outdoor air would be drawn into the attic which would then be pushed into the house which is at a lower static pressure which would then push the conditioned air out through the walls.
Depending on where the vapor barriers are in the walls, and where the insulation is in the walls (such as EIFS), you could be creating a moisture problem in the walls.
Whenever you install an exhaust fan, you will need to install sufficient intake openings to allow for the proper air flow with minimal depressurization of the space, with the reverse being true for installing intake fans - you need to allow sufficient exhaust openings to discharge that air for minimal pressurization of that space.
There are HVLP (High Volume Low Pressure) fans being used for large warehouse areas which are not as bad as they do not increase/decrease the static pressure in the space much while moving high volumes of air. However, those HVLP fans are frequently 8'-12' in diameter with slowly rotating blades ... I doubt those will fit in your gable end though ...
