The application of phase change materials to improve the climate resilience of a low-energy prototype house

Abstract

Due to a number of reasons including the effects of climate change and a shift towards a more widespread use of Modern Methods of Construction (MMC) for housing development, overheating issues in British homes has become a greater concern in recent years. Some of the most important advantages of MMC are the reduced use of materials, reduced construction time (particularly on site), reduced weather dependency, reduction of waste production, the possibility of reuse and recycling of components, and the possible lightness of the structure. MMC systems can deliver highly insulated, almost airtight homes, in line with requirements to reduce energy use for heating. However, they will generally have lower thermal mass than traditional construction and hence be less able to passively control temperature swings in warmer periods. This may contribute to uncomfortably high temperatures, which can affect the well-being and health of the occupants. The Mark Group Research House, a super insulated steel frame home, was designed to test MMC solutions and innovative technologies, and to be highly energy efficient. In previous work done by the authors, a computer model was used to investigate the house’s potential for overheating in today’s weather as well as in future climate scenarios. The authors have found that the house was generally comfortable but, despite the addition of mitigating strategies, presented a high risk of overheating that was aggravated when the future climate was considered. This risk was partially attributed to the low levels of thermal mass in the house. The integration of thermal mass, usually obtained through the use of exposed concrete or brick, can be problematical in MMC dwellings. The use of Phase Change Materials (PCM) may present a solution to this issue. PCM has been proven to work in a number of building applications but not much work has been undertaken investigating its applicability in housing. The work presented in this article reports on the integration of PCM in the Mark Group Research House as a solution to the overheating problem identified earlier. The results have shown that the PCM helps to regulate the temperatures in the house even when future climate scenarios are considered. However, it is only effective when coupled with an efficient ventilation strategy, which may not be an easy to implement solution because of its dependency on user behaviour.