Evaluating the Need and Potential of Equipping North American Houses with Multi-Zone VAV Systems

Abstract

To identify potential energy savings and improvements to thermal comfort in the Canadian residential sector, a survey on occupant behaviour and control of thermal environment was conducted from April-June 2009 in low-rise dwellings in Ontario, Canada. A total of 396 completed responses were received. Survey results show that approximately 20% of the respondents were not satisfied with their room temperature in the winter. Inadequate level of controllability to room temperature is perceived as the most serious problem. Problems associated with overheating during the winter and overcooling during the summer was also identified. Observations from the survey results helped identify the deficiencies of the heating equipments built today and suggest improvements should be made to increase the controllability of current systems. Thermal simulation was then conducted to identify the problems with single-zone systems commonly built today, and to investigate the potential retrofit alternative. Simulation results show that a multi-zone system can effectively mitigate the deficiencies suffered by existing systems and can drastically improve the energy performances of houses.