Air Handling Unit for Swimming Pool Climate Control: Innovative Solution for Limited Space
Initial Situation and Requirements
The main challenge lay in installing a replacement air handling system for the swimming pool at Rennerod Secondary School within a very limited plant room. This required an innovative, compact design for efficient dehumidification and outdoor air supply.
Technical Solution
The upright wall-mounted unit was designed in a modular way with top-mounted air connections and a corrosion-resistant coating. At the heart of the system is a crossflow heat exchanger with a downstream direct evaporator, complemented by an integrated refrigeration system with heat pump function and refrigerant condenser.
Dehumidification is performed in multiple stages: The pool exhaust air is first pre-cooled in the crossflow heat exchanger to just above dew point temperature with high energy efficiency, with heat recovery providing a large share of the required sensible cooling load. In the direct evaporator, the pre-cooled hall air is then dehumidified to the desired humidity level. The dehumidified air is returned to the plate heat exchanger, reheated, and used to pre-cool the hall exhaust air. Finally, in the refrigerant condenser, it is brought to supply air temperature using process waste heat.
When dehumidifying with dry outdoor air, the heat pump uses the remaining energy after heat recovery.
Operating Modes and Control
The system operates in three modes: pool operation (maximum dehumidification), standby mode (reduced dehumidification), and heating mode (rapid temperature increase). Control automatically selects the most efficient mode based on outdoor air conditions and usage requirements.
Energy Efficiency
High energy efficiency is achieved through the two-stage dehumidification process with heat recovery (efficiency up to 78%), demand-driven outdoor air control, and utilization of process waste heat.
Conclusion
This compact air handling system demonstrates how efficient swimming pool climate control can be implemented even in tight spaces. The solution is particularly well-suited for similar projects with spatial constraints.
Technical Data
Available installation area (H x W x D): 2120 + dampers (200 mm) x 2400 x 1100 mm
Unit dimensions (H x W x D): 2300 x 2400 x 1121 mm
Air volume flow (m³/h): 4,000
Cooling capacity in heat pump mode: max. 13.5 kW
Dehumidification performance: reduction of absolute humidity by up to 29 kg/h possible
Heating capacity (PWW): up to 18 kW on demand; in normal operation, total heating load is covered by heat recovery and refrigeration/heat pump system
Heat recovery efficiency: 78% (dry) and up to 90% (humid), depending on operating mode