Nazarbayev University’s School of Engineering and Digital Sciences (NU SEDS) researchers have published a first-of-its-kind critical review of review articles on phase change materials (PCMs) for thermal energy storage in buildings. This study was featured in the top-ranked journal Applied Energy, which boasts an Impact Factor of 10.1 and holds the #1 ranking in Building & Construction among 223 journals, placing it in the 99th percentile on Scopus.

The pioneering study was conceived at Nazarbayev University by Abrar Ahmad, a former MSc student who is now pursuing his PhD at Washington State University. During his time at NU, he worked as a research assistant under Associate Professor and Vice Dean for Research at SEDS, Dr. Shazim Memon. In this article, Ahmad critically analyzes 271 review articles on phase change materials (PCMs) for thermal energy storage in buildings, from the very first in 1983 through 2024. By unifying four decades of fragmented literature, it uncovers deeper insights and resolves inconsistencies that traditional reviews often overlook.

Dr. Shazim Memon highlights four key contributions of the publication:

• Global PCM database: The only comprehensive compilation of every commercially available PCM, complete with manufacturer details and direct website links.
• Literature mapping: Frequency analysis of 50 PCM topics—revealing understudied and well-worn topics—guiding researchers toward underexplored areas.
• Integrated assessments: Critical evaluation of PCM combined with natural ventilation strategies, thorough economic and environmental studies, and a cradle-to-grave life-cycle assessment for sustainable building design.
• Emerging frontiers: Machine-learning applications, novel performance indicators for real-world efficiency, and the circular-economy and climate-change implications of PCMs.

As Abrar Ahmad explains, his review stands out as an essential and practically useful tool for engineering practices, especially in countries with extreme climates, such as Kazakhstan.

“The review brings immediate practical value to countries that contend with large seasonal temperature swings, such as Kazakhstan, because it gathers in one place: (i) a complete catalogue of every commercially available PCM—including melting temperature ranges, latent heat values, and direct manufacturer links—drawn from forty years of literature, and (ii) a critical synthesis of how those materials have been tested in buildings, with and without nighttime ventilation, free cooling, or other passive strategies. Designers and code writers can therefore match a product’s phase change range to the heating and cooling loads of any climate and see, at a glance, the energy-saving and peak load-shifting achievable. In addition, the paper quantifies economic outcomes that are directly transferable to standards and incentive programs: for example, PCM-based free cooling systems that consume one-tenth the electricity of conventional split-type air conditioning and recover their extra capital cost in 3–4 years. Equally important, the review highlights where evidence is missing—only a handful of earlier reviews treat performance across multiple climate zones—thereby giving Kazakh regulators a clear research agenda to support future updates of SN RK 3.02-38-2013 ‘Energy Efficiency of Buildings.”

Regarding the construction industry's readiness to adopt phase change materials (PCMs) in countries with developing engineering ecosystems, such as Kazakhstan or other Central Asian nations, Abrar Ahmad provides insight:

“The construction sector in Kazakhstan is technically capable of adopting PCM solutions, but three factors emerge from the literature. Cost and freight: the review documents a 127 kg order whose shipping charges lifted the price to 74 USD/kg; locating regional distributors (Turkey, EU) or fostering local bio-based PCM production would halve that figure. The compiled studies on economic payback show static payback periods as short as 3–4 years for optimized free cooling systems, yet it can be significantly longer when climate, tariffs, or PCM placement are unfavorable—underscoring the need for project-specific life cycle costing before mass deployment. The commercial list supplies the technical data needed to assess products against existing Kazakh fire safety and insulation standards, while the review pinpoints frontier topics—machine learning optimization, circular economy strategies, and robust performance metrics—that remain largely unexplored. Targeted pilot projects (e.g., PCM wall retrofits in different climate zones of Kazakhstan) would both demonstrate local feasibility and fill those research gaps, paving the way for broader market uptake in Central Asia.”

The full version of the article can be read here: https://authors.elsevier.com/a/1l0t-15eifFuyh