If your home is sealed tight, then you should consider either an ERV or HRV system as well, depending on the humidity of your environment. They blow air out of

If your home is sealed tight, then you should consider either an ERV or HRV system as well, depending on the humidity of your environment. They blow air out of your house and replace it with fresh air from outside, which a fan could do, but they include a heat (and moisture, in the case of ERVs) exchanging plenum so that you don't lose all of the energy that you put into conditioning the air in your house. They're a little spendy in the $1,000 range, but if your issue is the inside air is too humid and moisture is building up on the walls and windows, it's a good system to use for comfort. You can also get a whole house humidifier / dehumidifier set for roughly the same price, but that doesn't provide fresh air for your house so I would only suggest that if your air cannot maintain the 30-50% humidity levels that are most comfortable for you with the ERV/HRV system.