Swimming pool heating technology: A state-of-the-art review

A large amount of heat is needed to maintain the thermal comfort of both indoor and outdoor swimming pools in cold seasons. This motivates the development of various heating technologies aiming to reduce energy use, as well as operating and investment costs. Although their development can be traced back to the 1960s, a comprehensive review of these technologies is lacking. Therefore, this paper presents a comprehensive review of the development of heating technologies for swimming pools. This review firstly introduces available heat transfer models that can be used to calculate or predict heat loss and heat gain for swimming pools. Then, different passive and active technologies are summarized. The active heating technologies used for indoor swimming pools include solar collector, heat pump, waste heat recovery, geothermal energy, and congregation technologies. The active heating technologies used for outdoor swimming pools include solar collector, heat pump, PCM storage, geothermal energy, biomass heater, and waste heat recovery technologies. A discussion is presented on the practical and possible heating techniques for swimming pool applications. Finally, through the reviewed literature, future research opportunities are identified, to guide researchers to investigate swimming pool heating systems with suitable and relevant technologies.