Say you go to bid on a customer's replacement air conditioner. You know that the owners have made some home improvements since their last unit was installed - they added new windows, say, or a new roof and insulation, or better flooring. Which of these improvements will have the most impact on their system's cooling load?
Glenn Hourahan, P.E., vice president of research and technology for the Air Conditioning Contractors of America (ACCA), wanted to find out. He evaluated residential building envelopes in various climates, and considered their effects on the HVAC load.