Experimental Investigation of Indoor Thermal Comfort under Different Heating Conditions in Winter

Owing to historical reasons, only a few locations in the Guangdong province use heating to enhance interior thermal conditions. With the variation in climate and increase in people’s lifestyle requirements, winter heating has become increasingly necessary. However, a literature review revealed that only a few studies have investigated the heating requirements during winter in the Guangdong province. In this study, we compared the thermal comfort of radiant floor heating with wall-mounted air conditioner heating. A Guangzhou University climate chamber was used in several investigations. The findings revealed that the thermal neutral temperatures of radiant heating and air conditioner heating were 22.0 °C and 23.0 °C, respectively, about 1 °C variation in temperature. Additionally, in the research on thermal reactions and local skin temperature measurements, the impact of local thermal discomfort on the overall thermal experience was also considered. The findings showed a direct relationship between the local thermal discomfort caused by radiant heating and general thermal sensation. Thermal sensation of the subjects mainly originated from the lower extremities and was significantly affected by Va (air velocity). The relationship between the local thermal discomfort of convective heating and general thermal sensation was weak and mainly caused by the uneven thermal environment. Thus, in south China, for lowering energy usage, radiant floor heating should be used to create an improved indoor thermal environment in winter

Analysis of SET* and PMV to evaluate thermal comfort in prefab construction site offices：Case study in South China

In urbanization, prefab buildings for office use are extensively utilized on construction sites owing to their convenience and flexibility. To study the applicability of standard effective temperature (SET*) and predicted mean vote (PMV) models in prefab construction site offices (PCSO), combined thermal parameter measurements and questionnaire surveys were conducted on selected construction sites in Guangzhou during the summer, autumn, and winter seasons. A total of 1505 valid questionnaires were collected. Based on the foundation of the adaptability theory, the data obtained through field studies were used to expand the applicability and reliability of the original PMV model and SET* model. This study found that the SET* and PMV models obtained in the current study cannot accurately evaluate the thermal comfort of people in the prefab building. In the cool condition, the original scale was lower than MTSV, and the conclusion is opposite under warm conditions. In addition, through calculation, it can be found that the natural SET* values were higher than the preferred SET* in three different seasons. The difference in preferred SET* was near 1 °C. The numerical values of the two types of models have been revised so that they can more accurately predict and evaluate the thermal comfort of a prefab building, thereby broadening the application scope of the PMV and SET* models. The modified models can thus be used to predict thermal comfort in prefab construction site offices