Study on the indoor thermal comfort of cave dwellings in cold areas of China

Cave dwelling, as a common traditional housing form in rural areas, has long been regarded as a low-cost, green, and environmentally friendly living choice. The purpose of this study was to explore and improve the thermal comfort of cave dwellings, and to systematically evaluate and analyse the thermal comfort of cave dwellings through a combination of visit surveys and indoor environmental parameter monitoring. After statistical analysis and comparison of the collected data, the following conclusions were drawn: (1) The thermal neutrality temperature of 25.15 °C determined by Predicted Mean Vote (PMV) in this study was greater than the thermal neutrality temperature of 19.49 °C determined by Thermal Sensation Vote (TSV) model, indicating that cave dwellers prefer a cooler thermal environments under actual conditions. (2) In cold weather, the maximum value of 80% acceptability is 18.12 °C and the minimum value is 12.00 °C. In hot weather, the maximum value of 80% acceptability is 27.17 °C and the minimum value is 23.66 °C. (3) In winter, the average indoor temperature of 9.71 °C is higher than the average outdoor temperature of 7.85 °C; In summer, the average temperature in the naturally ventilated room of 27.44 °C is much lower than the average outdoor temperature of 35.25 °C. The results showed that the building materials and structure of cave houses can provide a certain degree of thermal insulation, which can provide a basis for the design and improvement of low-cost, energy-saving and environmentally friendly houses in rural areas.