Dennis, I have a 40 year old house that we bought 3 years ago. One of the first things we did was to replace the old drafty windows. After much research we chose Pella because of the construction, gaurantee and of the wood on the inside part of the window. We wanted to keep the original look of the house. If not for the wood aspect, CertainTeed makes a real good replacement window. By the way our Pellas look great and operation and cleaning is a breeze. We just put central air in our ranch house also last year. Went with Trane high effeciency unit and received rebate back from the Power Company. Our electric bill has only gone up $25.00/month with the central air, believe high effencient unit pays for itself in a short period of time.