Before you cut too much ventilation - what direction is your prevailing wind in the winter?What direction does your ventilation face?
In SD, we can get very cold heavy winds... from the North and NW. My ventilation in on the south side. I leave it open 24/7/365.
In SD, we can get very cold heavy winds... from the North and NW. My ventilation in on the south side. I leave it open 24/7/365.