Hi, I own a colonial style house built in 1970 in new england. Our house has gable vents and a ridge vent, but no soffit vents. Part of the 2nd floor ceiling attaches to the bottom of the roof rafters so there is no clear air flow path to create a soffit vent (short of tearing the roof and sheathing completely off). My house orientation is east/west so I generally get good cross ventilation. This winter I discovered there was quite a bit of moisture in the attic. This spring/summer I was planning on installing a powered gable vent fan on the east side of the house to help pull air through. The question I am wondering is should I seal up the ridge vent or keep it? Sealing it up would create one entrance and one exit for the fan. Keeping it open would allow more air to escape the attic.
Any information is welcome!