Cooling efficiency of vests with different cooling concepts over 8-hour trials.

Ciuha, Urša; Valenčič, Tamara; Mekjavic, Igor B

As frequency and severity of heat waves are increasing, personal cooling systems are being considered as a tool to mitigate heat strain in workers in various occupational settings. The present study assessed cooling capacities (C; W·h·m-2) of various commercially available vests using different cooling concepts. Measurements were conducted over 8 h in a climatic chamber (Ta: 35 ˚C, RH: 35%) using a thermal manikin (Ts: 35 ˚C). Cooling power (P) and duration of efficient cooling (tc) determined the C value of each vest. Among the cooling concepts the active cooling vests were the most efficient, extracting 331 W·h·m-2, followed by the vests with phase change material (PCM) inserts, hybrid and evaporative vests, extracting a maximum of 164 W·h·m-2, 146 W·h·m-2 and 113 W·h·m-2, respectively. While some vests with PCM inserts provided intense but shorter cooling, evaporative vests provided mild but longer cooling throughout. Practitioner summary: The study assessed the cooling capacity of commercially available vests, using a thermal manikin. The vests present an affordable solution in various occupational settings where air-conditioning is not an option. A range of cooling capacities among different cooling concepts and vests of the same category were noted.