The demand for sustainable and energy-efficient building solutions has led to a growing interest in incorporating innovative technologies that optimize energy consumption while ensuring occupant comfort. One such technology gaining prominence is the use of Phase Change Materials (PCMs) for free cooling in buildings. PCMs offer a revolutionary approach to thermal management by leveraging the latent heat associated with phase transitions to regulate indoor temperatures. This essay explores the concept of using PCMs for free cooling in buildings, delving into their working principles, benefits, applications, and potential challenges.

Recently, Professor Abolfazl Ahmadi (Department of Energy Systems Engineering, Iran University of Science and Technology, Tehran, Iran) and his team (Professors and researchers from Switzerland and South Africa) published a paper titled “Energy consumption reduction in a building by free cooling using phase change material (PCM)” in Future Energy Journal.

The paper emphasizes the importance of energy storage systems, particularly latent heat thermal energy storage (LHTES) systems, which offer advantages due to their minimal temperature variation and higher energy storage density. The study focuses on cooling a room in Zanjan, Iran, using Carrier software, and then delves into a numerical analysis of a free cooling system employing commercial paraffin RT25 as a PCM. The investigation considers the effects of storage tank flow rate and inlet air temperature during the charging and discharging processes. The simulation results indicate that paraffin solidifies within 4 hours when exposed to airflow with a 20°C temperature at night. The stored cold energy of 1.4 kW is released through the PCM, enabling a free cooling system to operate for 2.1 hours during a July afternoon in the room. This research underscores the potential of LHTES and PCM for efficient cooling and energy management (to read more, download this open-access paper).

As the demand for sustainable and energy-efficient buildings grows, the market for PCM products is expected to expand. This increased demand can lead to economies of scale, potentially reducing the cost of PCM materials and installation. The economic viability of using PCMs for free cooling in buildings is a complex consideration that involves analyzing initial investment costs, energy savings, regional climate conditions, and potential incentives. While PCM solutions may require a higher upfront investment, long-term energy savings, improved occupant comfort, and potential incentives can contribute to a positive return on investment and overall economic benefits for building owners and occupants.