Review of fan-use rates in field studies and their effects on thermal comfort, energy conservation, and human productivity.

• This study presents a comprehensive review on fan-use rates and effects in practice. • The main trigger of fan-use is a warm environment rather than building types. • Using fans elevates neutral temperature averages by 3 K in real buildings. • More than 15% air-conditioning-use rate is reduced by fan-use in buildings. • 3-K temperature extension is achieved by using fans for productivity not decreasing. This paper is a literature review of field studies on fan-use rates and their effects on thermal comfort, energy conservation, and human productivity. In the assessed literature, fans are more popular in Asia, and more used in mixed-mode (MM) and naturally ventilated (NV) buildings than in air-conditioned (AC) buildings. On the basis of collected fan-use models, probit regression models of fan-use rates and ambient environments were obtained and indicate that the essential trigger of fan-use is a warm environment rather than building types. This result helps us to understand the control behaviors and comfort requirements of occupants. Also, fans could provide benefits in three aspects: widening neutral temperatures, saving energy, and improving occupants' productivity. First, using fans in buildings elevates the neutral temperature and the upper limit of neutral zone (0.5 thermal sensation scale) averages by about 3 K in ranges from 25.7°C to 28.7°C and 27.5°C to 30.7°C, respectively. Second, fan-use reduces AC-use rates in MM buildings in summer. The regression models based on the collected AC-use rate models illustrate that, on average, AC-use is expected to be reduced by about 15% in summer when fans are used. Third, providing occupants access to fans could improve occupants' productivity. Based on the limited data available, a 3-K temperature extension is achieved by fans ensuring productivity not decreasing. This review could shed some light on the extension of the neutral temperature range, predictions of MM buildings' energy consumptions, and methods to enhance productivity. Additionally, this review suggests some valuable directions for future research on fans. [ABSTRACT FROM AUTHOR]