Energy efficiency and the misuse of programmable thermostats: The effectiveness of crowdsourcing for understanding household behavior

•Crowdsourcing services were used to study how people use thermostats.•Crowdsourced data was verified by comparing self-reported data with uploaded photos.•This procedure revealed inconsistencies and misconceptions in thermostat usage.•One third of programmable thermostat owners had programming features disabled.•Online crowdsourcing is a valuable tool for collecting energy usage data in homes.