Active thermal mass enhancement using phase change materials

Whiffen, T.R.; Russell-Smith, G.; Riffat, Saffa

Abstract

Buildings account for around 40% of energy consumption in the UK. For over twenty years active thermal mass systems have been a feature in low-energy buildings in northern Europe. By passing ventilation air, and utilising night ventilation, through the hollow core structures efficient heating and cooling has been achieved. Despite the success, such systems suffer from space overheating and efficiency losses during extended hot periods. Control strategies have largely mitigated this effect however low cost retrofit solutions that enhance the system are of interest. This research therefore investigates the benefit of using innovative phase change material (PCM) solutions to enhance thermal comfort and reduced energy usage of traditional active thermal mass systems.

A prototype PCM enhancement was constructed, with energy saving and comfort benefits investigated under controlled laboratory conditions. In absolute terms the PCM solution offered an additional 12.5% energy storage capacity and a 29% increase in active surface area, coupled with the existing sensible thermal mass. Under laboratory conditions the PCM addition saved an additional 0.1 kWh per day, delayed AC onset by 1.2 h and offered an average 1.0 °C reduction in room temperature during 8 h of fixed internal heat gain, contrasted against the original active thermal mass system.

Citation

Whiffen, T., Russell-Smith, G., & Riffat, S. (2016). Active thermal mass enhancement using phase change materials. Energy and Buildings, 111, https://doi.org/10.1016/j.enbuild.2015.09.062

• Journal Article Type: Article
• Acceptance Date: Sep 24, 2015
• Online Publication Date: Sep 28, 2015
• Publication Date: Jan 1, 2016
• Deposit Date: Oct 27, 2017
• Publicly Available Date: Oct 27, 2017
• Journal: Energy and Buildings
• Print ISSN: 0378-7788
• Electronic ISSN: 0378-7788
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 111
• DOI: https://doi.org/10.1016/j.enbuild.2015.09.062
• Keywords: Active thermal mass ; Phase change materials ; Thermal mass ; Free cooling ; Night cooling ; Energy-efficient cooling
• Public URL: https://nottingham-repository.worktribe.com/output/768199
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0378778815303017?via%3Dihub