Last year I purchased a 50-year-old home. Central air and heating were installed about 12 to 15 years ago, which included five vents in the basement. I had an energy conservation expert from the local electric company do a survey of the home. He suggested that I seal off all five vents in the basement since there was no living space down there. A little later my HVAC expert came to examine the system. He said I needed to keep those vents open as the system was designed to move air through those vents. Otherwise, I was building up too much pressure, causing extra strain on my HVAC system. What's the best way to go? How can I be the most energy-efficient and save money in the long run?