Inter-personal factors affecting building occupants' thermal tolerance at cold outdoor condition during an autumn-winter period

The study was conducted to investigate thermal adaptation and the impact of individual differences on developing thermal tolerance when the outdoor temperature falls below 10 degrees C. The applicability of the predicted mean vote (PMV) model was investigated, too. The concept of occupant's 'Temperament' was evaluated as a psychological-adaptation factor. Two main hypotheses were: (a) people with different temperaments would experience different thermal sensations and (b) the classic PMV- predicted percentage dissatisfied (PPD) model is capable of predicting the neutral sensation in heated buildings under cold outdoor temperatures. There was a direct relationship between individual temperament and clothing level as well as thermal sensation. The occupants who were assessed to have cold temperament tend to wear thicker clothes and were more sensitive to variations in indoor air temperature than others. Females with a cold temperament were more than twice as likely to be affected by indoor air temperature as those with a warm temperament. The PMV-PPD model was able to predict the mean neutral temperature in the heated buildings even when the outdoor temperature fell below 10 degrees C. However, when occupants were able to control high indoor temperature, the percentage of true prediction of actual mean votes by the adaptive thermal heat balance model was more than that by the classic PMV model.