Llop Gestió, the company who is in charge of the facility management of CEM Vallirana sport complex, has implemented several energy efficiency measures, demonstrating its commitment to sustainability issues. The energy audit conducted in the framework of STEP-2-SPORT project revealed huge energy savings potential, and one of the aspects highlighted was the inefficient operation of the pool dehumidifier. As pool dehumidifier represented around 60% of energy usage of the whole building, CEM Vallirana decided to refurbish it, incorporating new energy efficient elements and repairing old components.

The dehumidification unit is connected to both the air distribution system and the pool water circulation system. The refurbished unit includes a Demand Controlled Ventilation (DCV) system with the aim to adjust the amount of outdoor ventilation based on the level of CO2 in the swimming pool building. The carbon dioxide level is monitored by two CO2 sensors, one located in the return airstream and the other one for monitoring CO2 levels from the fresh outdoor air supplied. When occupancy levels are low, the ventilation rate is reduced to minimal levels causing a reduction in the energy usage. Variable Speed Drives in the supply and return fans have been installed to minimize energy consumption.

Maintenance actions have also been conducted to improve the energy performance of the unit, such as the repair of refrigerant leaks in compressors and cleaning actions of evaporator and condenser coils. The free cooling and recirculation dampers have also been replaced since the old ones were not operating correctly. With the new dampers installed, now it is possible to recover the energy from the fresh outdoor air during summer period. The mixing box is the section of the pool dehumidifier used to mix the return air flow with the outside air flow.

 

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After 5 months of its implementation the results are very encouraging since 42% of thermal savings have been achieved, saving within this period nearly 8,000€. Improved indoor air quality and better humidity control are other significant benefits of the new system installed. In addition, the system includes a tablet which allows maintenance staff display in real-time the key parameters of the pool dehumidifier, such as CO2 concentrations, supply and return temperatures, Relative Humidity (%), hours of operation of compressors, etc.