I have a problem keeping the second floor of our house cool in the summer with air conditioning, especially during these recent hot days. The second floor is noticeably warmer than the first floor, usually 5-10 degrees. I want to get some opinions on some solutions to this problem.
The house, built in 1993 in southern Ohio, is about 2400sf with 3 bedrooms on the second floor. It has a geothermal heating/cooling system which works really well and is efficient, except for the second floor problem in the summer. The system is not zoned, and the thermostat is on the first floor. All of the second floor bedrooms have both a floor register and return air ducts in the ceiling, in addition to a return air duct in the hallway. The walls are standard 2×4 with fiberglass insulation with Ã‚½” foam board insulation over that. The attic insulation is blown-in to a depth of 6-8 inches, probably not enough, but I read somewhere that more may not help much with this problem. Last year I installed a whole house fan in the second floor hallway ceiling, this of course only helps when the temperature outside is less than the temperature inside (on cooler evenings).
It seems to me that I need to get the heat out of the attic. Some possible solutions I have looked into include an attic fan that automatically runs during times of high temperature and humidity, and stapling a foil radiant barrier to the bottom of the rafters to shield the attic from the heat absorbed by the shingles. What is the effectiveness of each of these remedies? Is there anything else I should look into?
Thanks in advance for your help.