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This study aims to investigate thermal environment and occupant local thermal sensation in offices with cooling ceiling. A field survey combining environment measurements and questionnaires was conducted in offices in Zhuhai, China. The obtained results indicated that compared with experimental conditions, occupants in real crowded offices experienced warmer environment because the mean radiant temperature (MRT) was higher than the air temperature due to the shelter effect of indoor furniture etc. MRT also showed higher correlations with both overall thermal sensation (OTS) and overall thermal comfort (OTC) than air temperature because a great part of heat transferred through radiation. Air temperature showed linear correlation with the ceiling temperature when cooling ceiling could fully handle the cooling load, but supplementary air cooling was also necessary for radiant cooling systems in real offices. Moreover, local thermal sensation (LTS) of different body parts showed great differences due to many factors such as clothes and adaptive behaviors, and it significantly influenced both OTS and OTC. Particularly, head, hand, leg and foot had considerable effects on OTS while head and leg showed influences on OTC. In addition, this paper also validated against some important results of previous studies and provided references for future work. [ABSTRACT FROM AUTHOR]

Indoor thermal environment design parameters have a significant impact on human thermal comfort, health and building energy consumption. The methods of determining indoor thermal environment design parameters in China and around the world are mainly based on the PMV model. This method often results in certain errors deviations from the actual situation and has difficulty reflecting the differences in the thermal environmental requirements in different climate regions, seasons, building types, etc. This paper proposes a data-driven method based on Chinese Thermal Comfort Database and uses a logistic regression to obtain the indoor air temperature range that 80% of occupants find thermally acceptable under different conditions. The results indicate that the prediction of this model are in good agreement with the actual data and have as higher accuracy in predicting the percentage of thermal acceptability than a linear regression method. This model shows that different regions, seasons, and building types have different acceptable temperature ranges and that the acceptable air temperature ranges are on average 2.0 °C wider than the ISO 7730 and 0.7 °C wider than the GB50736-2012. This method is conducive to the determination of air temperature thresholds and better reflects people's equirements for thermal environment under different conditions. [ABSTRACT FROM AUTHOR]

• Two thermal comfort investigations were conducted in severe cold area. • The thermal neutral temperatures derived from the linear regression model and logistic model were compared. • The relationship between probability of opening windows and temperature difference was developed. In recent years, the indoor air temperature in residential buildings for space heating rose gradually in the severe cold area of China. Would people feel comfortable in a warmer environment? This paper focuses on the appropriate indoor air temperature in winter. Two field investigations were conducted on the indoor thermal environment and human adaptation in residential buildings with district heating in Harbin during two winter seasons from 2011 to 2014. Ten apartments and their residents were chosen as samples in each investigation. The investigations included measurements of physical environmental parameters as well as subjective questionnaires. The results show that when the indoor air temperature was higher than 24 °C, people would have a sensitive response and preferred a lower temperature. An ordinal logistic regression model was used to examine the result of the linear regression model. The neutral temperature derived from the logistic model is 0.5 °C higher than that from the linear model and the adjusted neutral temperature is 0.8 °C higher than the linear model. Detecting whether people felt "cool" or not and "warm" or not is relatively accurate with the logistic model. It is not sensitive to judge whether people felt "neutral" in low air temperatures. Thermal neutral temperature is not a suitable set-point of indoor air temperature. In the severe cold area of China, the indoor air temperature of 20 °C is suggested as the standard for space heating in residential buildings in terms of comfort and energy saving. [ABSTRACT FROM AUTHOR]