Well-designed residential thermal environments that meet the comfort and health needs of elderly individuals can enhance their well-being and decrease associated health risks, which is one of the foundations of sustainable building development. However, limited evidence on thermal response patterns and thermal comfort needs of rural elderly leads to insufficient support for improving thermal environments. This study was conducted in seven villages in Xi’an, a cold region of China, and both subjective questionnaires of thermal comfort and objective physical environment tests were adopted. Correlations between nine kinds of human subjective responses and thermal environmental parameters were examined. The neutral values of operative temperature, relative humidity, and air velocity were calculated to be 23.9 °C, 63.3%, and 0.28 m/s, respectively. Comfort ranges for temperature, humidity, and air velocity were determined to be ≤29.3 °C (80% acceptability), 43.3–81.0% (80% acceptability), and 0.16–0.41 m/s (90% acceptability). Clothing insulation of rural elderly in summer was relatively higher and less sensitive to temperature shifts. The slope value of the thermal adaptative model was larger, with higher comfort temperatures in warmer environments. These results are the outcome of the prolonged adaptability to the regional climate and the poor indoor thermal environment, as evidenced by lower psychological expectations, higher behavior adjustment, and environmental decisions influenced by household low income. The findings in this study can be used as a basis for the design or improvement of residential thermal environments for rural older adults.

In areas where solar energy is abundant, such as the Tibetan plateau, passive solar buildings are attracting more and more attention and becoming a popular form of rural building. However, it is often difficult to achieve the satisfactory indoor thermal environment in a local rural passive solar single-family house. In order to improve the indoor thermal environment of passive solar buildings through building design, a systematic study of rural single-family buildings in Tibet was conducted. The basic parameters were investigated on the outdoor thermal environment, space-arrangement, envelope structure, and the indoor thermal environment. The building model considering space-arrangement modes was developed based on the survey data in multi-space passive solar buildings. The general physical and mathematical analysis models of multi-space passive solar buildings were established based on the heat transfer theory. Furthermore, the effects of space-arrangement and exterior wall thermal resistance on indoor air temperature were analyzed by numerical simulation. Results show that the indoor air temperature of the passive solar building is influenced by space-arrangement and wall thermal resistance together. When the space-arrangement of the building model was changed from “north-south through type” (mode a) to “through and separation combination” (mode b) and “north-south separation” (mode c), the indoor air temperature of the living room increased from 8.8 °C to 10.6 °C and 11.6 °C, with increases of 20.5% and 31.8%, respectively. In addition, equally increasing the thermal resistance of exterior walls in different orientations has different effects on the indoor air temperature. In the space-arrangement mode c, comparing with the temperature increment of the living room and bedroom caused by increasing thermal resistance of the south wall and north wall, the temperature increment of the living room caused by increasing thermal resistance of the east/west wall increased by 151.7% and 32.7%, and that of the bedroom increased by 609.1% and 239.1% respectively. This study can provide a reference for the optimal design of passive solar buildings in solar energy abundant areas.

Efficient use of solar energy by thermal energy storage composites and utilizing environmentally friendly cementitious materials are important trends for sustainable building composite materials. In this study, a paraffin/low density polyethylene (LDPE) composite shape-stabilized phase change material (SSPCM) was prepared and incorporated into a sulphoaluminate cement (SAC) mortar to prepare thermal energy storage mortar. The thermal and mechanical properties of SSPCM and a SAC-based thermal energy storage material (SCTESM) were investigated. The result of differential scanning calorimeter (DSC) analysis indicates that the latent heat of SCTESM is as high as 99.99 J/g. Thermogravimetric analysis demonstrates that the SCTESM does not show significant decomposition below 145 °C. The volume stability test shows the volume shrinkage percentage of the SCTESM is less than that of pure SAC mortar and far less than that of ordinary Portland cement mortar. The SCTESM has high early strength so that the compressive strength at 1-, 3-, and 7-day curing age is up to that at 28-day curing age of 67.5%, 78.3%, and 86.7%, respectively. Furthermore, a mathematical prediction model of the SCTESM compressive strength was proposed. The investigation of latent heat storage characteristics and the thermoregulating performance reveals that SCTESMs have the excellent capacity of heat storage and thermoregulating.

Space layout design has been recognized as a key technical challenge in achieving low-energy and low-carbon rural houses. Adjustment of room location can influence building energy performance and is subject to both meteorological and design parameters. To elucidate the impact of these parameters on the energy saving potential of room relocation (ESR), this study investigated rural houses in Northwest China using dynamic simulations to compare the relative energy saving rates (RES) associated with three types of single heated room location changes: from the west side to the middle (WM), from the east side to the middle (EM), and from the west side to the east side (WE). Simulations were conducted across different climate regions (Lhasa, Xi’an, Tuotuohe, and Altay) and design parameters, including exterior wall U-value, building orientation (BO), building height (BH), and window-to-wall ratio (WWR). Additionally, the maximum differences in energy consumption (MD) among six layouts with multiple heated rooms were assessed. The results demonstrated that ESR varied significantly with room relocation. The ranges of RES_WM, RES_EM, and RES_WE were −7.89% to 13.20%, −7.82% to 10.25%, and −2.29% to 3.36%, respectively. The MD values ranged from 2.42% to 15.01%. For single heated rooms, including direct normal irradiance (I_dn), the difference between east and west solar-air temperature (△T_sa), outdoor dry bulb temperature (T_e), exterior wall heat transfer coefficient (U), and WWR significantly influenced RES_WM and RES_EM. The ranking of the factor contributions was U > △T_sa > I_dn > T_e > WWR for RES_WM and U > I_dn > △T_sa > T_e > WWR for RES_EM. In the case of RES_WE, I_dn, △T_sa, T_e, exterior wall U value, and BO had significant effects, ranking I_dn > △T_sa > T_e > BO > U. For MD, the key influencing factors were I_dn, △T_sa, T_e, exterior wall U value, and WWR, which were ranked as I_dn > △T_sa > U > T_e > WWR. The effects of design parameters on ESR varied under different climatic conditions. In high-temperature regions, the exterior wall U-value had a stronger influence on the ESR of WE. In regions with larger |△T_sa|, BO exerted a more pronounced effect on the ESR of WE. In regions characterized by high temperatures and radiation, WWR and BH significantly influenced the ESR of WM and EM. Similarly, in these regions, WWR and BH exhibited a greater impact on MD. Finally, among the meteorological parameters, I_dn and △T_sa were significantly correlated with ESR (p < 0.01). These findings provide a valuable reference for the energy-efficient layout design of rural houses in Northwest China and cold regions and support the future development of intelligent and automated rural residential spatial layout design.

This study investigates the cooling potential of night ventilation and the climate adaptability of local vernacular buildings in the Turpan basin, aiming to identify passive energy-saving design strategies. A rural building with an air-drying shelter was selected for summer indoor environment measurements (two stages: all-day window closure vs. night ventilation), and a numerical model was established to simulate the impacts of window-to-wall ratio and window shading projection factor on the indoor environment. Results indicate that night ventilation introduces cool outdoor air to replace indoor hot air, cools building components, improves thermal comfort, and reduces cooling energy demand. Without additional cooling technology, increasing the window-to-wall ratio lowers nighttime temperatures but increases Degree Discomfort Hours, while appropriately sized shading devices mitigate daytime overheating from larger windows. Benefiting from the high thermal storage capacity of earth-appressed walls, semi-underground rooms offer better comfort with lower temperatures and higher humidity; for aboveground rooms, orientation is critical due to intense solar radiation. The air-drying shelter reduces solar radiant heat absorption and inhibits convective/radiative heat transfer on the roof’s external surface, significantly lowering its temperature from noon to midnight. This leads to notable reductions in the roof’s internal surface temperature (1.02 °C in the sealed stage, 2.09 °C during night ventilation) and the average indoor temperature (1.70 °C).