The In-Situ Implementation Of A Feature-Rich Thermostat: A Building Engineering And Human Factors Approach To Improve Perceived Control In Offices

It is well understood that the ability to control the thermal environment through a thermostat interface can increase thermal comfort and productivity in offices. Despite this knowledge, even in offices where thermostats are provided, many people still report poor perceived control. This study applied theories of thermal comfort, human factors, and building technology to improve perceived control in 25 offices in an institutional building in Ottawa, Canada. First, we audited the building automation system in the context of perceived control and combined these findings with survey responses from the occupants to assess likely barriers to usability. In this building, contextual setpoint control caused by zoning, poor response times, and uncommunicated scheduled setbacks were likely barriers to control. We then applied a human factors framework to develop and implement features into the existing thermostat's software interface. The features we developed aimed to help users better understand the complexity of their system, heating status, times of scheduled setbacks, and estimates of the timeto-temperature after they made setpoint adjustments. Detailed feedback from a small group of users indicated value in the features; however, there was a mixed perception of the implementation. The results show promise, and we recommend future iterations of this design be tested and refined.