Center for Research in Energy Systems Transformation (CREST)

Here we present a field study examining the impact of elevated room temperature and air movement on thermal comfort and self-reported productivity. This experiment was performed in three environmental conditions (one with a set-point of 23 °C—a typical set-point used in Singapore—and two elevated (up to 28 °C) room temperature conditions). Occupants had shared control of ceiling fans.

The results show that the most comfortable thermal condition, with thermal sensation closest to neutral, is achieved at a room temperature of 26 °C with operating fans. Increasing the temperature set-point from 23 °C to 26 °C resulted in a significant increase in thermal acceptability (from 59% to 91%), and a 44 kWh/m2yr savings in electrical energy used for comfort cooling. We found that a room's set-point temperature can be increased up to 27 °C without creating a negative impact when controllable air movement is provided compared to an environment with a set-point of 23 °C. Thermal satisfaction is significantly higher in spaces of 26 °C with operating fans, than when the room's temperature is set at the typical 23 °C. Moreover, the relative humidity in the office is decreased from 62% (when the temperature was 23 °C) to 50% when the temperature was 27 °C.

Occupant's self-reported ability to concentrate, be alert, and ability to be productive was comparably high in all conditions. The results indicate that work performance is poorly correlated with room temperature, but increases with greater individual thermal satisfaction.