Field evaluation of dynamic bedroom air-temperature control for sleep in real homes: implementation fidelity and exploratory sleep outcomes

Abstract: Lab-based findings suggest that a “fall–rise” temperature profile aligned with nightly thermoregulatory changes during sleep may improve sleep. However, such profiles have not yet been experimentally tested in real-world bedrooms. We built a scalable research prototype that applies a predefined night-time temperature profile to typical split-type air conditioners using an infrared smart controller. The dynamic temperature profile is set to +1 °C relative to each participant’s habitual setpoint before sleep, returned to the habitual setpoint at bedtime, then lowered to −1 °C during the early sleep period, and finally returned to the habitual setpoint during the later sleep stages. We conducted a micro-randomized trial with 18 participants in Singapore, collecting at least 30 study nights per participant, and evaluated both implementation fidelity and sleep-related outcomes. Overall, 44% of the 285 valid dynamic nights met the alignment criterion, meaning that the temperature profile achieved in the bedroom matched the target temperature profile. Nine homes were classified as aligned, while the remaining nine were not aligned. This rate was lower than we expected, showing that the target profile is often hard to achieve in real bedrooms. Under dynamic control, participants reported a stronger preference for a cooler pre-sleep environment (p < 0.05), while the overall sleep outcomes showed no clear intervention effects. Overall, the prototype showed that the profile could be implemented in some homes, but the 44% alignment rate represents limited implementation success and is not sufficient for reliable deployment. Future studies should focus on improving implementation fidelity through pre-deployment bedroom screening and calibration.

Keywords: Thermal comfort; Occupant-centric; HVAC control; Sleep environment; Wearable sensors; Sleep quality

Full text available at: ScienceDirect

Code and dataset available at: GitHub

Recommended citation: Zhang, W., Chong, A., Zhang, H., Schiavon, S., & Miller, C. (2026). Field evaluation of dynamic bedroom air-temperature control for sleep in real homes: implementation fidelity and exploratory sleep outcomes. Building and Environment, 304, 115100. doi:10.1016/j.buildenv.2026.115100