Field demonstrations, laboratory studies and design resource development.
Funding Sources: CALIFORNIA ENERGY COMMISSION EPIC FUNDING IN-KIND SUPPORT FROM BIG ASS FANS AND CBE PARTNERS
The goal of this project is to demonstrate energy savings and improved comfort through the integration of smart ceiling fans and smart thermostats in retrofit applications. Secondary goals are to identify and address market barriers to adoption of this strategy, provide guidance on how to implement this technology into energy efficiency retrofit programs and policies, and develop industry resources: standard rating methods, a design guide, and energy code language to facilitate widespread implementation.
As of summer 2019 the research team has installed monitoring equipment in four multi-family sites, installed the smart fans and thermostats surveyed the office workers and residents who occupy the common rooms and a small number of dwelling units, and continue to monitor the effects of raised indoor temperature and use of ceiling fans to reduce energy consumption while maintaining comfort. The project team has also conducted numerous laboratory tests to understand the impact of numerous fan design parameters.
Significance to Industry
The advent of cooling workplaces and homes through air conditioning has provided thermal comfort that leads to improved satisfaction and productivity, especially in the last few decades, but with tremendous costs. Ninety percent of American homes have air conditioning, contributing to climate change and leading to physiological “addiction” that causes people to become less tolerant of temperatures outside of a narrow range.
Air movement, such as through ceiling fans, can cool a person indoors but uses only a tiny fraction of the energy required by HVAC systems. New fans, using only one to eight watts can offset a 6ºF increase in indoor air temperature. This improves occupants comfort and perceived air quality while decreasing energy consumption. Allowing higher indoor temperatures reduces a building’s total HVAC energy by an average of 5% per degree F, and by even more in climate zones where natural ventilation or evaporative cooling systems are used instead of compressor-based cooling, or in areas with a large number of air-side economizer hours (such as many parts of California).
ASHRAE formed a new standard to stipulate standard methods of testing fans, and its Comfort Standard 55-2013 now has an integrated approach to evaluating comfort effects of air movement ranging from desirable air speeds. However, designers still lack guidance for designing rooms with ceiling fans (spacing, sizing, cooling effect). Tools for design and evaluation are completely absent at the moment and are needed for reliable design.
The overarching goal of this project is to conduct primary research to yield understanding and insight regarding the energy use patterns and customer acceptance of an integrated solution for smart ceiling fans and learning thermostats in both dwelling units and common areas of multifamily buildings.
The work includes a demonstration pilot focusing on retrofit applications in affordable housing because the technology has the potential to meet this market segment’s need for increased occupant comfort, low cost per energy saving, low operational level of effort, and ease of retrofit. Multifamily buildings provide the opportunity to develop the solution and demonstrate its application in both dwelling units and common areas. Common areas include spaces that will inform commercial application opportunities.
An interdisciplinary team from industry and academia have installed smart ceiling fans and smart thermostats in four multifamily sites in California’s Central Valley. The innovative integrated solution includes a Haiku ceiling fan from Big Ass Fans and smart or communicating thermostats, such as EcoBee. The SenseME comfort based ceiling fan controller embedded in the Haiku fan will optimize energy use and occupant comfort. This integrated solution provides a higher level of energy-comfort optimization by automatically increasing setpoints during cooling mode with auto-adjusted fan speed for comfort, and automatically de-stratifying in heating mode.
The work will also include a series of laboratory tests to discovers the impact of various parameters: multiple fans in a space, ceiling height and fan diameter.
Publications and Reports
He, Yingdong, Wenhua Chen, Zhe Wang, Hui Zhang. 2019. Review of fan-use rates in field studies and their effects on thermal comfort, energy conservation, and human productivity. Energy and Buildings. Volume 194, 1 July 2019, Pages 140-162. DOI: 10.1016/j.enbuild.2019.04.015.
Gao, Yunfei, Hui Zhang, Ed Arens, Elaina Present, Baisong Ning, Yongchao Zhai, Jovan Pantelic, Maohui Luo, Lei Zhao, Paul Raftery, Shichao Liu. 2017. Ceiling fan air speeds around desks and office partitions. Building and Environment. Volume 124, 1 November, pp. 412-440. DOI: 10.1016/j.buildenv.2017.08.029
Present, Elaina, Paul Raftery, Gail Brager, Lindsay T. Graham. 2019. Ceiling fans in commercial buildings: In situ airspeeds & practitioner experience. Building and Environment. 147 (2019) 241–257.
Raftery, Paul, Jay Fizer, Chen Wenhua, Yingdong He, Hui Zhang, Edward Arens, Stefano Schiavon, & Gwelen Paliaga. 2019. Ceiling fans: Predicting indoor air speeds based on full scale laboratory measurements. Building and Environment. DOI: 10.1016/j.buildenv.2019.03.040.