Analysis and simulation of performance data for residential solar heating and heat pump system in Seattle, Washington. Final report

Abstract

The Pacific Cascades is a distinct climatological region for solar energy applications. In order to investigate the effect of the regional differences in solar energy availability on residential solar heating systems, a study was conducted to analyze the performance of a solar heated house in this region and to validate a solar heating and heat pump computer simulation program for this region. The house, called the Seattle City Light Project Weathervane house, uses solar energy from roof-top flat plate collectors to boost the performance of a water-to-air heat pump. If the temperature of the water storage tank drops too low, then auxiliary heating is provided by an off-peak immersion heater. Performance data for the ten-month heating season was collected from Seattle City Light, and put into the form of a comprehensive baseline data document during this study. The University of Wisconsin TRNSYS solar heating computer simulation program was used to model the performance of the house. The computer results were compared to the actual performance data in order to help validate TRNSYS with regional solar heating data. The computer results were also used to help in understanding the behavior of the Seattle City Light Project Weathervane house heating system. Actualmore » solar heating system performance demonstrates that approximately 40 percent of the total house heating requirements were provided by the solar heating system. The impact on utility peak load requirements was reduced by the off-peak auxiliary heating requirements. Significant heating was supplied by hot water taken directly from the storage tank when the water storage tank temperature was high. The computer program modeled the heating system behavior qualitatively hour-by-hour, and over periods of a week or greater, the simulation also agreed quantitatively with the energy used by the actual heating system. Details of the analysis and results are presented.« less