Study On The Thermal Comfort In Hospital Wards

Hospital is a medical facility with the purpose of health maintaining, returning and keeping. Currently, the principle of hospital HVAC design mostly follows the common HAVC system, and the thermal environment parameters setting for different functional zones is less targeted or purposeful. And there is little research on thermal comfort in wards, the design and operation effect of HAVC system can not meet the occupants’ special requirements in wards. Recently the current situation has been paid more and more attention. This paper relies on the National Natural Science Foundation project, namely “Research on the basic issues of health comfort effects of thermal and humid environment in hospital buildings”(No.51278506) to research on the thermal comfort in wards. The study would lay a foundation to establish a thermal comfort model suitable for patients in the wards. The results would provide basic data to the thermal comfort standard setting, and theoretical support to HVAC design, operation and management in wards.Firstly, both the domestic and foreign field studies on thermal comfort of the hospital are summarized. To make up the deficiencies of existing researches, the thermal comfort model in sleeping environments is employed to estimate the thermal sensation of the prone patients, and the calculation model suitable for prone position is adopted to calculate the total thermal insulation of the bedding system. What’s more, EQ-5D health questionnaire is used for the quantitative evaluation of the patients’ health status.Secondly, the field experiment was performed in wards of general hospitals both in winter and summer. The experiment contained the subjective investigation and the thermal environment measurement, which was conducted strictly according to Evaluation standard for indoor thermal environment in civil buildings. It is found that the predicted thermal sensitivity in winter and summer and the predicted neutral temperature in summer by Fanger’s PMV model and the thermal comfort model in sleeping environments are very close to the actual values, and there is a big difference between the predicted neutral temperature and the actual value in winter. Compared with the healthy population of other building type, the patients in the wards have a higher neutral temperature in winter and a lower one in summer, and the patients are less sensitive to the thermal environment.Lastly, the suitability of PMV model for the thermal comfort of the patients in the wards has been analyzed.The results showed that there exists discrepancy between the objective predicted PMV values and subjective actual TSV values, and the PMV model apply well around the thermal neutrality. The Binary logitic regress model of the difference between subjective and objective thermal sensation is established considering the influence factors such as operative temperature, relative humidity, activity level, EQ-5D value, gender, disease department, age, days of hospitalization and BMI value. The result indicates that all the factors in the logistic model have no significant influence on the difference between subjective and objective thermal sensation in summer, and operative temperature, EQ-5D value, disease department,activity level have a significant influence on it in winter. It is suggested that the PMV model need modification if used to predict the thermal comfort of the patients in the wards.