Thirty Years of Performance of an Active Solar Space Heating/DHW System

A solar house in Knoxville, Tennessee has been operating for thirty years providing space heating and domestic hot water. The active system with air collectors and rock storage and heat pump back up has required minimal maintenance. Using data from sub-meters, the auxiliary and operating energy have been compared for the first three years of operation and the last eight years. There appears to be little or no degradation in performance during the thirty-year period.