A novel model to assess the energy demand of outdoor swimming pools

In the Mediterranean region, outdoor swimming pools, despite having lower energy consumption compared to indoor pools, are nonetheless highly energy-intensive structures, offering significant opportunities for energy efficiency improvements. Although there are numerous studies in the literature, few of these works have been dedicated to estimating the energy consumption of outdoor pools while considering typical local meteorological conditions and their occupancy rates. This paper presents a novel energy balance model for outdoor pools that incorporates the latest correlations for calculating evaporation due to forced convection and sky temperature, a new phenomenological model for assessing the enhancement of evaporation as a function of occupancy rate, and an approach that takes into account atmospheric stability conditions in defining wind-related heat losses. The model successfully predicts the annual energy consumption data for outdoor Olympic swimming pools in Greece with a mean absolute percentage error of less than 12 %. Simulations of an outdoor swimming pool operating with water at 26.5 C and in which the cover is not used present indicate a specific thermal energy consumption of about 2300 kWh/m2. A decrease in water temperature by 1 C and the use of a cover result in approximately 11 % and 30 % reduction in consumption, respectively.