Experimental investigation of latent thermal energy storage in high-rise residential buildings in Toronto

Recent architectural trends in high-rise apartments are characterized by highly transparent facades. Higher window to wall ratios (WWR) entail larger thermal exchanges, and consequently longer thermal discomfort periods and increased energy consumptions for space conditioning. This study investigates the potential of passive latent heat storage using Phase Change Materials (PCM) as a retrofit measure in high-rise apartments in Toronto. A novel composite PCM system comprised of two commercial PCM products with different melting temperatures of 21.7 °C and 25 °C is proposed. This system is experimentally investigated using small scale test cells exposed to the weather of Toronto from July to October 2016. Five different tests were conducted while different variables were monitored to assess the indoor temperature and heat storage patterns. Results indicate significant extreme temperature reduction and daily temperature fluctuations reduced by 6 °C using the PCM system investigated in this paper. Moreover, incorporating two melting points in one zone proves to be very effective both in summer and fall months.