I have an old house from the 40's in northern VA. In the summer, the attic is quite hot. The house has central ac through the same ducts as the heat. Worst case, I think I may buy a portable AC unit to help the finished attic out. It may be possible to upgrade the insulation at some point, but my budget is limited.. so between now and then, I was curious about your experience with duct boosters to try and bring more of the cold air from a very efficient a/c unit upstairs?