M. Haneda’s scientific contributions

A subjective experiment was conducted in a climate chamber to investigate the effects of thermal discomfort (feeling too warm) on the performance of office work. Twenty-seven Danish female subjects were exposed in a climate chamber to four conditions with different levels of thermal discomfort provided by a combination of operative temperature and amount of clothing. Thermal sensation votes towards the end of exposures were neutral, slightly warm, warm and very warm. More symptoms indicating mental fatigue were observed with increased thermal discomfort. The subjects reported that more effort was necessary when they felt thermally warm compared to conditions in which they felt thermally neutral and slightly warm. Performance of proof-reading, addition and text-typing tasks was not affected by thermal discomfort. This suggests that the subjects were able to maintain their performance but as a result they got more tired and the mental work load increased.

The main objectives of this paper were to examine the physiological reactions of the occupants being the result of thermal discomfort and whether these reactions have consequences for the performance of office work. Thirty-two Danish female subjects performed simulated office work in a chamber at four combinations of operative temperature and clothing insulation to obtain different levels of thermal sensation from neutral to warm. Thermal sensation votes were strongly correlated with the temperature of the skin. Skin moisture increased at increased temperatures. Tear-film stability and blinking rate were not affected. Concentration of salivary alpha-amylase and cortisol decreased with increased thermal discomfort which may suggest that the performance of simulated office work could be affected, but it was not. Carbon dioxide concentrations were similar in different conditions suggesting that the metabolic rate of subjects was unchanged, but the subjectively reported work load and effort increased significantly with increased thermal discomfort.

The main purpose of this study is to evaluate the effects of thermal satisfaction improvements on productivity by introducing cooling methods. A subjective experiment was conducted in a climate chamber conditioned at 25.5°C and 28.5°C. Lighter business wear corresponding to COOLBIZ and three additional individual cooling methods were introduced in the conditions at 28.5°C. Thermal sensation was lowered, thermal satisfaction was improved and fatigue after tasks was decreased, with higher degree of freedom in the selection of individual control of thermal environment. There is a possibility that performance was improved and fatigue was lowered by improving thermal satisfaction of occupants by introducing simple individual cooling methods, even under raised present cooling temperature.

In this study, work place productivity was evaluated by task performance and fatigue. The relationship of fatigue and task performance was studied by using the data of the controllable and uncontrollable illuminance level conditions with Task and Ambient Lighting system. When the subjects could control their task lights, performance of the triple digit multiplication task was significantly higher (p=0.01) and text typing test was tend to be higher (p=0.09) than that when they could not control the task lights. There was significant negative correlation between fatigue level of subjects and their performance of the multiplication task and text typing test.