Integrating Smart Ceiling Fans and Communicating Thermostats for Energy-Efficient Comfort
November 30, 2022
Energy Research and Development (500)
Electric Program Investment Charge - EPIC
Paul Raftery, Dana Miller, Hui Zhang, Therese Peffer, Gail Brager, Lindsay Graham, Elaina Present, Ed Arens, David Douglas-Jaimes, Gwelen Paliaga, Andy Brooks, Sebastian Cohn, Mitch Greene
This research project identified and tested the integration of smart ceiling fans and “communicating” thermostats. These highly efficient ceiling fans use as much electricity as an LED light bulb and have onboard temperature and occupancy sensors for automatic operation, based on space conditions. The Center for the Built Environment (CBE) at UC Berkeley led the research team including TRC Companies (TRC), Association for Energy Affordability (AEA), and Big Ass Fans (BAF).
The research team conducted laboratory tests, installed 99 ceiling fans and 12 thermostats in four affordable multifamily housing sites in California’s Central Valley, interviewed stakeholders to develop a case study, developed an online design tool and design guide, outlined codes and standards outreach, and published several papers.
The project team raised indoor cooling temperature setpoints and used ceiling fans as the first stage of cooling; this sequencing of ceiling fans and air conditioning reduced energy consumption, especially during peak periods, while providing thermal comfort. The field demonstration resulted in 39 percent measured compressor energy savings during the April-October cooling season when compared with baseline conditions. Weather-normalized energy use varied from a 36 percent increase to 71 percent savings, with median savings of 15 percent across all of the 13 compressors that were measured. This variability reflects the diversity in buildings, mechanical systems, prior operation settings, space types, and occupants’ schedules, preferences, and motivations. All commercial spaces with regular occupancy schedules showed energy savings on an absolute basis before normalizing for warmer intervention temperatures, and 10 of 13 sites showed energy savings on a weather-normalized basis. The ceiling fans provided cooling for one site for months during hot weather when the cooling equipment failed. Occupants reported high satisfaction with the ceiling fans and improved thermal comfort. This technology can apply to both new and retrofit residential and commercial buildings.