Human Thermal Comfort And Productivity During Exposure To Moderate Temperature Ramps

With the deepening study of human thermal comfort, more and more scholars focus on the dynamic environment. Dynamic environment includes many aspects, such as the change of temperature, wind speed, humidity. Temperature is the key of the research. Gagge and Woyn are the representative scholars in the field of dynamic thermal comfort. Through a series of research, they got the laws of human action under transient environment and built some models to predict thermal sense. However, people spend more time in the same indoor environment. Transient environment mainly exists in the transition between the different environment and its research had some limitations. Compared to the transient environment, the research under temperature ramp-change environments aims at the control of one same environment temperature ramp-change, which is more in keeping with normal life. People could make the most of adaptive abilities themselves and enhance the function of human physiological regulation system in the dynamic environment where temperature changes gradually. Furthermore, indoor temperature can affect people’s work efficiency. Many scholars had got the influence mechanism in steady environment, but the research in dynamic environment remains to be further explored. Therefore, the study of thermal comfort in the temperature ramp-change environments contributes to understand the characteristics of human thermal responses and explore the effect of temperature ramp-change on productivity, which is significant to improve people’ work efficiency. Meanwhile, the research will be useful to explore the dynamic control strategies of air-conditioning.To study the change of occupants’ thermal comfort and work efficiency under temperature ramp-change environments, experiments of six different temperature conditions were conducted in the artificial climate chamber of Chongqing University during July, 2014. 16 college students participated in the experiments of totally 96 times. The range of temperature change is 22℃~26℃、26℃~30℃ and the rate of temperature change is 0.1℃/min、0.2℃/min. During the experiment, subjects were asked to fill out the questionnaires according to their subjective feelings and to do the test of work efficiency by the way of mental multiplication. Meanwhile, the environment parameters and subjects’ physiological parameters were measured. The results found that there were good linear relations between human thermal sensation and indoor air temperature and skin temperatures under temperature ramp-change environments. The study also showed that there is one-to-one relationship between air temperature and thermal sensation and skin temperature couldn’t be used to predict thermal sensation. It could be explained that the thermal experiences have great effect on occupants’ skin temperature and there are great differences of mean skin temperatures to different initial environments. Besides, the rate of temperature change has slight effect on human thermal sensation but has significant effect on the change rate of occupants’ skin temperatures in this experiment. Based on the subjects’ thermal response characteristics under temperature ramp-change environments, the paper modified the related models built by the thermal comfort term of Chong Qing university and further establish the human thermal response model, which improve the applicability of the model.When studying the people’ productivity under temperature ramp-change environments, the results suggested that a moderate temperature change rate can stimulate the brain excitement, which keeps people in the best conditions.The indoor environments, as a long-term remain space, would have a great effect on human body. Therefore, according to the occupants’ thermal responses under temperature ramp-change environments, the paper has taken into account of meeting human thermal comfort, improving people’s work efficiency and proposed the indoor dynamic control strategies of air-conditioning in summer.