Experimental study on a passive heating system integrating solar and geothermal energy for temporary facilities

To address the low thermal resistance and poor thermal storage capacity of temporary facilites’ envelope structures, this study proposes a passive heating system that integrates solar energy and shallow geothermal energy. The winter heating performance of the system was experimentally tested in Xinjiang region. In addition, the effect of enhancing the thermal resistance of the building envelope on indoor thermal environment was studied. The experimental results show that the passive solar heating system can raise the temperature of outdoor air to above 20 ℃ for approximately 7.5 hours, demonstrating a significant heating effect. The indoor air temperature increas with an average rise of 5.3 ℃ and a maximum rise of 8.3 ℃ . Under the regulation of the passive system, the indoor temperature remains above 0 ℃ throughout the day. Furthermore, improving the thermal resistance of the building envelope reduces the impact of outdoor environmental conditions on the indoor thermal environment. When a heating system is in operation, enhanced envelope insulation can effectively reduce indoor heat loss and help maintain a relatively stable indoor thermal environment.