Comparative Efficiency of Space and Water Heating Appliances

Abstract

This paper describes a laboratory investigation to determine the comparative energy consumption of different types of appliances used for domestic space and water heating. of particular concern was the efficiency of the appliances when operating under changing seasonal thermal loads typical of conditions in a dwelling. The effect of alternative control systems was also to be examined. The type of space heating considered was limited to systems using low temperature hot water. Oil and gas space heating and electrical water heating appliances were included in the study. For a comparative assessment of the different types of heating and domestic hot water production the performance of the various appliances was measured when the appliances were subjected to a set of “reference” daily heat load profiles. The load profiles corresponded to the demand imposed by the space heating and domestic hot water requirement of a typical dwelling, taking account of system control characteristics and representative weather conditions. From the test programme figures were determined for the seasonal efficiencies and fuel consumptions of central heating appliances when operating under practical conditions of use. The influence of system controls on efficiency was also determined, and the sensitivity to variations in occupancy and dwelling parameters has been assessed.