Two passive measures to use solar energy for container houses in cold regions

This is the authors' abstract. We don't add key points for this paper.

Container houses, as a kind of temporary buildings, feature steel envelopes with high thermal conductivity and low heat capacity, leading to excessive heating energy consumption in cold regions. This study investigates two passive energy efficiency measures, namely attaching a sunspace and integrating phase change material (PCM) into the envelopes. Field tests were conducted to measure the indoor air temperature and interior envelope surface temperature of a container house in the Yanqing Competition Zone of the Beijing Winter Olympic Games. Indoor air temperature was also monitored for a small-scale sunspace integrated with PCM on the campus of Beijing University of Civil Engineering and Architecture. These obtained data were applied to validate the simulation approach. Then, three container house simulation models, namely, the baseline model without a sunspace or PCM, the model fitted with a sunspace only, and the model integrated with both sunspace and PCM, were constructed to explore the effects of the two passive energy efficiency ways. Under meteorological parameters at three elevations of Yanqing Competition Zone of the Beijing Olympic Winter Games, indoor temperature and heating energy consumption were analyzed for these three models. The results indicate that both measures effectively mitigate indoor temperature fluctuations, cut envelope heat loss, and reduce the heating energy consumption of container houses. Compared with the baseline container house, the integration of a sunspace reduces annual heating energy consumption from 2,401.0 kWh, 2,999.3 kWh and 3,425.6 kWh to 1,911.2 kWh, 2,419.9 kWh and 2,781.0 kWh at elevations of 950 m, 1,839.9 m and 2,177.5 m, corresponding to energy-saving rates of 20.40%, 19.32% and 18.82% respectively. Further energy conservation is attainable when PCM is incorporated into sunspace-fitted container houses. It is also found that adhering PCM on indoor side of the insulation layer provides better energy-saving effects than on outdoor side of the insulation layer. Specifically, the indoor-side incorporation of 40 mm PCM delivers further energy savings of 14.52%, 13.28%, and 12.75% at the three corresponding elevations, lowering the annual heating energy consumption to 1,562.6 kWh, 2,021.6 kWh, and 2,344.3 kWh in sequence. Unlike most previous studies examining combined passive strategies for permanent buildings, this research evaluates the applicability of two passive energy-efficiency measures adopted in container houses under cold climate conditions. The simulation-based method and simulation results provide references for enhancing the heating energy efficiency of container houses located in cold regions.