Occupant control patterns of low temperature air-to-air heat pumps in Chinese rural households based on field measurements

Currently, household heating systems in rural China primarily use coal. This low-efficiency heating method not only results in poor indoor comfort, but also contributes to indoor and regional air pollution. Split-type, low temperature air-to-air heat pumps (AAHPs) have been proposed to be a clean heating alternative to replace coal-burning stoves. This study performed field measurements of a AAHP product in two representative rural households in suburban Beijing, China, focusing on three goals: 1) to observe, analyze, and validate occupant control patterns of low temperature AAHPs in rural households; 2) to explore comfort indoor temperature levels in rural households and demonstrate the thermal comfort achieved as per the individual requirements of residents and space use; and 3) to learn the heating energy saving potentials achieved by considering occupant control patterns. Room temperatures and time-varying electricity consumption from February 6 to March 15 were monitored. Three occupant control patterns were observed and verified from the field measurements: 1) continuous daily operation of heat pumps, 2) intermittent operation, and 3) irregular operation. In addition, the observed indoor temperatures of both households ranged from 10 °C to 23.5 °C. By considering varied occupant control behaviors, the heating energy consumption reduction can be significant. This study indicated that using the low temperature AAHPs met individual thermal comfort requirements and had a great potential to reduce the heating energy consumption when considering different occupant control patterns.