Understanding the role of inhabitants in innovative mechanical ventilation strategies

The causes and implications are explored for why some inhabitants choose to avoid or abandon usage of their mechanical ventilation system. Over half of respondents in four LEED-certified high-rise residential buildings in Toronto, Canada, were found not to use their heat recovery ventilators (HRV). Questionnaire scores, comments and interview results found the following reasons: acoustic dissatisfaction, difficulty with the accessibility of filters, inhabitant knowledge and preferences, and lack of engagement with training materials. A disconnect also exists between the expectations of designers and the thinking and behaviours of inhabitants. The implications of inhabitants' ventilation behaviours were also explored though metered energy data as well as noise and indoor air quality (IAQ) measurements within their dwellings. Results suggest that abandoning mechanical ventilation in favour of passive ventilation can actually lead to greater satisfaction with IAQ and to decreased energy consumption. It is recommended that designers employ resilient design strategies that allow for varied preferences (e.g., for passive ventilation) to be exercised by inhabitants without undermining suite- or building-level performance. The study also highlights the importance of using post-occupancy evaluation methodology to understand how inhabitants interact with (new) technology in order to optimize performance and satisfaction in high-rise residential buildings.