The purpose of this paper is to summarize the most recent composite results of analysis performed by Vitro Laboratories of solar space heating data for selected active sites in the National Solar Data Network (NSDN). Results presented have been developed on the basis of analysis of instrumented sites maintained through the 1979-1980 heating season.

This paper provides summary-level results of data collected for those sites having complete seasonal performance results. Primary concentration is on five specific site results representative of solar heating system operation for residential sites. Results are presented in NSDN nomenclature. Inferences based on the measured values are presented in the conclusions. The measured values represent the reduction of thousands of individual sensor readings that have been filtered and converted to engineering units. Reduction of site data has been carried out by a rectangle rule method, modified for integration of sequential data with a potentially variable time step.