Inadequate wet area ventilation leads to moisture precipitation (indoor rain), mould (consequence of bacteria growth), odour (consequence of mould), degradation of materials (consequence of all + salt) and unhealthy environment (respiratory problems).
Indoor pool areas are not just another room. Careful consideration needs to be exercised when planning and building such areas especially where water is to be heated. Air ingress dictates where egress is to be located on the roof.
Wet area ventillation
Wet areas need continuous and effective ventilation and in an appropriate manner. Fundamental to venting a pool enclosure is peripheral air entry, approx 400 mm from ground level, and a having central convergence of the air mass prior to discharging to atmosphere. The higher the peripheral air ingress, the greater the incidence of moisture precipitation within the building, especially with a heated water mass without adequate ventilation.
Remember....the greater the activity, the higher the humidity levels and the greater the need for ventilation whether natural or powered ventilation
Cross flow venting
Cross flow venting is inefficient and never appropriate for heated enclosures.The venting of wet area heated enclosures require continuous air movement, from high flow to trickle flow.
Dehumidifiers are a refinement to a theme, but should never be the theme itself, as they cannot replace fresh air or introduce oxygen as natural ventilation products offer.
The covering of a heated pool mass is also essential in reducing power consumption. This creates less demand of the ventilation system employed whether it be natural ventilation or powered ventilation products such as dehumidifiers.