Relative importance of temperature, draft, noise and window area in offices.

Achieving optimized partial improvements of the indoor climate may often be better than to know all optimal levels. The purpose of this study was to investigate the relative importance of temperature, noise, draft and window area. 30 heat-acclimatized subjects participated in 10 exposures in single person climate chambers. Each exposure lasted three hours. During an exposure, the subject was free to optimize the operative temperature at a link to either draft, noise or window area. For each pair of parameters, three linear links were tested. A reference exposure was furthermore included without any link. Results show that a decrease in operative temperature of 1 °C gives the same decrease in annoyance as approximately 0.1 m/s decreased air velocity, 7 dB(A) decreased noise level or 0.5 m2 increased window area. The used trade-off method may have numerous other research applications.