Abstract Food transport and storage at low temperatures is a matter worldwide due to changes of the dietary habits and the increasing of the population. The issue of improving food storage applies at different applications such as commercial freezers or refrigerated trucks. The aim of this work is to improve the thermal performance of commercial freezers using phase change materials (PCMs) under door openings and electrical power failure. A commercial PCM was selected (Climsel-18) with a melting temperature of −18 °C, which is contained in 10 mm thick stainless steel panels placed at different locations in the freezer. During 3 h of electrical power failure, the use of PCM maintained the freezer temperature 4–6 °C lower and that of the frozen products remains at acceptable levels for much longer time. With frequent door openings the benefit of the PCM is evident when the temperature of the cabinet is near the melting temperature of the PCM.