Thermal Comfort Comparison and Cause Analysis of Low-Temperature High-Humidity Indoor Environments of Rural Houses in Gansu Province, China

Low temperatures and high humidity often occur in the northern basins and mountainous regions of China. This research reveals a common winter indoor environment in this rural areas characterized by low-temperature and high-humidity indoor thermal conditions. Improving this environment directly with equipment would inevitably result in significant energy consumption. Therefore, comprehending the thermal performance mechanisms of different structural building materials is of vital importance as it provides crucial baseline values for environmental improvement. This study conducted a survey utilizing user questionnaires, resulting in the collection of 214 valid responses. Additionally, a local experiment regarding thermal comfort was conducted. Simultaneously, this study monitored the indoor physical environments of these houses (a sample of 10 rooms was taken from earth houses and 12 rooms from brick houses). Parameters measured on site included air temperature, relative humidity, light illumination, and CO 2 . The results showed that the humidity inside the earth houses is more stable and regression models can be developed between thermal sensations and temperature for long-term residents. The residents of these earth houses are more sensitive to temperature step. In contrast, the residents of brick houses, experiencing greater environmental variability, demonstrated lower sensitivity and greater adaptability to temperature changes. In addition, heating from bottom to top is more comfortable and healthier for the residents of brick houses in Gansu. Moreover, it is more favorable for the inhabitants’ livelihood to regulate the temperature steps to a maximum of 4 °C. This study provides valuable reference information for the future design of houses in low-temperature and high-humidity environments.