Motivations and Actions of Human-Building Interactions from Environmental Momentary Assessments

TL;DR

This study investigates how occupant motivations, routines, and discomfort influence human-building interactions and demand response program overrides, using ecological momentary assessments from households to understand behavioral patterns affecting energy management.

Contribution

It provides novel insights into the motivations behind occupant actions affecting demand response effectiveness, highlighting the limited role of thermal comfort alone.

Findings

Thermal environment reactions are the most common motivation.

Nearly half of responses are motivated by non-thermal factors.

Certain actions like activity changes are less reported during thermostat-triggered EMAs.

Abstract

The expansion of renewable electricity generation, growing demands due to electrification, greater prevalence of working from home, and increasing frequency and severity of extreme weather events, will place new demands on the electric supply and distribution grid. Broader adoption of demand response programs (DRPs) for the residential sector may help meet these challenges; however, experience shows that occupant overrides in DRPs compromises their effectiveness. There is a lack of formal understanding of how discomfort, routines, and other motivations affect DRP overrides and other related human building interactions (HBI). This paper reports preliminary findings from a study of 20 households in Colorado and Massachusetts, US over three months. Participants responded to ecological momentary assessments (EMA) triggered by thermostat interactions and at random times throughout the day. EMAs included Likert-scale questions of thermal preference, preference intensity, and changes to 7 different activity types that could affect thermal comfort, and an opened ended question about motivations of such actions. Twelve tags were developed to categorize motivation responses and analyzed statistically to identify associations between motivations, preferences, and HBI actions. Reactions to changes in the thermal environment were the most frequently observed motivation, 118 of 220 responses. On the other hand, 47% responses were at least partially motivated by non-thermal factors, suggesting limited utility for occupant behavior models founded solely on thermal comfort. Changes in activity level and clothing were less likely to be reported when EMAs were triggered by thermostat interactions, while fan interactions were more likely. Windows, shades, and portable heater interactions had no significant dependence on how the EMA was triggered.