Field survey of heat recovery ventilation systems: occupant interactions.

The installation of packaged heat recovery ventilation (HRV) systems has recently become common practise in new homes in Canada. Despite improvements in product quality and reliability, HRV systems are only capable of providing safe, continuous, efficient and effective ventilation if homeholders have a understanding of the basic operation and maintenance procedures and the system's interaction with other house systems. Furthermore, homeholders must be able to perceive the value of HRV systems if they are expected to operate them. Canada Mortgage and Housing Corporation initiated a research project to determine the degree to which homeholders are capable, or willing, to interact with HRV systems. HRV systems within fifty-eight, regionally representative houses of various age were inspected to characterise the condition and performance of the systems as found. Interviews were conducted with the occupants to determine their understanding of the operation and maintenance requirements of their HRV systems and their perceptions of system value, effectiveness and efficiency. V\lhile most occupants reported an understanding of the operation and maintenance needs of their NRV systems certain disparities exist. For instance, more than half of the systems surveyed had immediate service requirements such as filter, heat recovery core and intake grille cleaning. More than half of the systems had unbalanced supply and exhaust air flows. Ventilation rates were found to be substandard in 60% of the homes surveyed. The occupants of tract built homes demonstrated the least appreciation of the operating and maintenance requirements of HRV systems. The configuration of the HRV systems ductwork and the availability of controls also was found to have an influence on occupant interactions. This investigation demonstrated that most homeholders appear willing and able to interact with HRV systems. More consumer education and refined (user-friendly) control and maintenance strategies are required to ensure the successful adoption of HRV systems within Canadian homes.