Swimming pool ventilation

Heat and moisture

Evaporation from the water surface to VDI 2089, and the dehumidifying airflow it calls for.

Swimming pool ventilation

Moisture gain and dehumidification calculation

Pool parameters

Moderate activity

Indoor climate

Calculation method

Evaporation is computed from the formula VDI 2089 (Germany), the accepted standard for swimming-pool design.

  • Evaporation rate depends on bather activity, water surface area and the difference in vapour pressure.
  • Moisture removal: The fresh air needed to hold the target humidity, usually 55–60 %.
Tip: Covering the water surface outside opening hours cuts running costs — it reduces evaporation by up to a factor of ten.

When the outdoor air is humid (in summer), ventilation alone may not dehumidify. A mechanical dehumidifier or air conditioning is then required.