Experimental evaluation of passive cooling using phase change materials (PCM) for reducing overheating in public building

¹ Centre for Built and Natural Environment, Faculty of Engineering, Environment and Computing, Coventry University, Sir John Laing Building, Much Park Street, Coventry, CV15FB, UK.
² Exergy, Coventry University Technology Park, Puma Way, Coventry, CV1 2TT, UK.
³ Phase Change Material Products Limited, Unit 32, Mere View Industrial Estate, Yaxley, Cambridgeshire, PE7 3HS, U.K

^* Corresponding author: abdullahi.ahmed@coventry.ac.uk

Abstract

Indoor Environmental Quality (IEQ) is essential for the health and productivity of building users. The risk of overheating in buildings is increasing due to increased density of occupancy of people and heat emitting equipment, increase in ambient temperature due to manifestation of climate change or changes in urban micro-climate. One of the solutions to building overheating is to inject some exposed thermal mass into the interior of the building. There are many different types of thermal storage materials which typically includes sensible heat storage materials such as concrete, bricks, rocks etc. It is very difficult to increase the thermal mass of existing buildings using these sensible heat storage materials. Alternative to these, there are latent heat storage materials called Phase Change Materials (PCM), which have high thermal storage capacity per unit volume of materials making them easy to implement within retrofit project. The use of Passive Cooling Thermal Energy Storage (TES) systems in the form of PCM PlusICE Solutions has been investigated in occupied spaces to improve indoor environmental quality. The work has been carried out using experimental set-up in existing spaces and monitored through the summer the months. The rooms have been monitored using wireless temperature and humidity sensors. There appears to be significant improvement in indoor temperature of up to 5°K in the room with the PCM compared to the monitored control spaces. The success of PCM for passive cooling is strongly dependent on the ventilation strategy employed in the spaces. The use of night time cooling to purge the stored thermal energy is essential for improved efficacy of the systems to reduce overheating in the spaces. The investigation is carried within the EU funded RESEEPEE project.