This research continued to gather operational performance data and maintenance experience on a retrofit residential solar space heating system. Data analysis includes comparison to prior years' results. Separate chapters are devoted to analyzing the performance of evacuated tube collectors and the home's reaction to sole dependency on solar energy during a selected winter period. Considerable attention is given to actions that were taken to prepare the system for a return to normal occupancy (the home was vacant until October 1979). Information concerning the perceived need for development of an operations and maintenance manual and a 'homeowner's' manual is included. Complete copies of the developed manuals are appendices to this report. (Author)