PH-79-07A-4 -- Energy Calculation Procedures for Residences with Field Validation

Energy demand by the residential sector constitutes approximately twenty percent of the total United States energy demand. The Ohio State University under Phase One of a contract from the Electric Power Research Institute investigated fuel utilization in nine Columbus, Ohio residences. The primary objective of this research effort was to develop and field validate procedures for predicting hourly thermal loads and associated energy requirements of residences. Field research work began in the spring of 1974 and terminated in the fall of 1975.

The topic of this paper is the development and field validation of computerized procedures for simUlating the performance of residential heating and cooling systems. Central forced-air systems studied are gas-fired, electric resistance, air-to-air heat pump, and direct expansion air-conditioning systems. In-space electric baseboard systems were also studied.

Available literature on modeling residential systems is limited. Generally, the performance of residential systems is considered steady-state utilizing concepts such as part-load efficiencies, fuel utilization efficiences, coefficients of performance, or seasonal performance factors. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) suggests a modified degree day procedure based on full load efficiencies (1). The ASHRAE procedure is simple, however signifigant errors in estimating fuel requirements may occur for periods less than a season. Little success has been achieved in applying the procedures to cooling energy requirements.

A need for truly dynamic system models was recognized. Thermal load analysis using dynamic methods was available yet no link was made to the transient characteristics of the heating and cooling systems. This research focused on investigating the dynamic link between structure loads and system performance.

Citation: ASHRAE Transactions, Volume 85, Part 1, Philadelphia, PA



Product Code(s): D-PH-79-07A-4