Perceptions of thermal conditions in contemporary high-rise apartment buildings under different temperature control strategies

Abstract

While occupancy-based control and other demand management control strategies have demonstrated potential, little is known about how these changes in heating, ventilation, and air-conditioning (HVAC) control impacts occupants’ perception of the thermal conditions in their home. In this paper, occupants’ thermal comfort perceptions and use of thermostat overrides under three different control strategies (programmable thermostat operation, occupancy-reactive control, and pre-cooling/pre-heating for load shifting) are analyzed. Thermal comfort data were collected through six occupant surveys administered to 54 participants in the summer and winter months in two high-rise condominium buildings in Toronto, Canada. Minor changes to reported thermal sensation scores were observed in both the occupancy-based and load shifting control scenarios, however, overall reported thermal sensation scores remained neutral. Occupants’ use of overrides did not change significantly during occupancy-based control periods, however, during load shifting control, occupants frequently overrode strategy temperature setpoints – which indicates that many participants likely experienced thermal discomfort beyond their tolerance level. Occupants’ use of strategy overrides during load shifting control strategy operation in the cooling season significantly reduced strategy efficacy. Reducing the maximum temperature setback during load shifting control to 3 °C during the cooling season was recommended to reduce occupant override and improve realized peak-period load reductions.

Acknowledgments

The authors would like to thank the participating condominium boards, suite owners and renters, and property management personnel at FirstService Residential for their assistance in acquiring data for the study. The authors would also like to thank ecobee for their support, funding and hardware contributions throughout the project and Enbridge and Toronto Hydro for their financial and in-kind support. This work was funded in part by the Natural Sciences and Engineering Research Council of Canada (NSERC) (RGPIN-2016-06325), The Atmospheric Fund (TAF), the Independent Electricity System Operator (IESO), and the Ontario Centres of Excellence (OCE) Voucher in Innovation Program (VIP). This work has benefitted from the thoughtful discussions with our colleagues in IEA EBC Annex 79.

Additional information

Notes on contributors

Helen Stopps

Helen Stopps, Student Member ASHRAE, is a PhD Candidate.

Marianne F. Touchie

Marianne Touchie, PhD, PEng, Associate Member ASHRAE, is an Assistant Professor.