Thermal Comfort in a Naturally Ventilated Environment with Supplementary Cooling and Heating

Abstract

A longitudinal study was conducted from March 1995 to November 1997 to investigate occupant responses to the thermal environment in a suite of offices located in the Architecture building at Sydney University. The rooms are ventilated through operable windows and doors and are provided with background heating from wall panel radiators in winter. Seven of them with 17 regular occupants have on demand supplementary cooling and heating equipment. An adjoining group of five rooms with five occupants does not have this facility. Measurements of air temperature, relative humidity, mean radiant temperature and air velocity were collected from time to time at occupied workstations together with reports prepared concurrently by the occupants with details of their thermal sensations, clothing and activities. A total of668 data sets were collected from occupants of rooms with cooling/heating and 143 sets were collected from people without it. It is reported that all respondents were able to adapt to a range of temperatures by passive means but those who had access to supplementary cooling/heating were observed to use it to limit upper and lower temperatures to a range from about 20°C to 27°C Monthly mean PMV was computed for the sample with cooling/heating and found to be within the range from—0.4 to + 0.6. Actual mean votes were a little higher except in February 1995 and February 1997. It would seem, however, that mean votes have little or no meaning in the light of changing requirements of respondents as demonstrated by the considerable variability of acceptable temperatures.