THERMAL COMFORT STUDY ON OUTDOOR DINING

Abstract

Thermal comfort field studies were conducted at four outdoor dining locations to get a general understanding of people’s thermal comfort perceptions in the tropics. The profile of the environment parameters (i.e. air temperature, mean radiant temperature, relative velocity and relative humidity) was presented and compared between the afternoon and evening sessions in a summary table.

Subjective assessments were carried out simultaneously to investigate the actual thermal comfort level of the diners. Results were presented as a combination of both sessions. Direct and indirect assessment of thermal acceptability were also examined. Comparison between thermal sensation votes (TSV) and comfort sensation votes revealed that although people voted in the hot region of ASHRAE scale, they found the environment comfortable. Regression analysis was applied between TSV on the ASHRAE scale and the environmental parameters to investigate their correlations. The findings showed that air velocity had the strongest relationship with TSV. Thermal neutrality of the diners was also investigated by plotting the actual TSV and theoretical Predicted Mean Vote (PMV) against operative temperature. It was found that neutral temperature using actual TSV was higher than that of theoretical PMV.

Lastly, percentage of people thermally comfortable was calculated using three thermal indices and compared with the actual Bedford votes. Results showed that tropical PMV equation developed for outdoor thermal comfort use was a better approximation of the actual percentage compared to other indices. It was highlighted that this study is not a representation of typical conditions as measurements at the four locations only constituted a snapshot of the environment.