RESIDENTIAL HOT WATER - A BEHAVIORALLY-DRIVEN SYSTEM

Residential water use was intensively studied in 7 houses, using electronic recorders and open-ended interviewing. These houses exhibited large variation in total hot volume (89-5061, daily) and in heat used per person (6. 5-16. 9 MJ daily). The variation is attributed primarily to behavioral differences among the occupants. In most houses, bathing accounts for the largest volume use, while the kitchen accounts for the largest number of uses and the second largest volume. A measure of piping-distribution efficiency is defined as heat deliverd to the tap over heat sent from the water tank. Small-volume uses are frequent and are very inefficient but account for only a small proportion of the total hot water. Total piping-distribution efficiencies, in the two houses for which they could be computed, were 0. 91 and 0. 88.