Today the concept of indoor bathing areas and the benefits to be derived from them is taken for granted, but unfortunately the necessity of ventilation is forgotten until a problem arises.
Deterioration of building materials due to excessive moisture absorption is a common occurrence. The lack of appropriate ventilation causes costly repairs, which could have been prevented.
Correct enclosure design is paramount in ensuring that the building provides the maximum benefits whilst requiring minimal maintenance. Too much is made of trying to have the pool enclosure conform to the overall design theme of the home without appropriate consideration to the essential fundamentals.
Wet areas need continuous and effective ventilation, and in an appropriate manner. Fundamental to venting a pool enclosure is peripheral air entry 600 mm from ground level, and a central convergence of the air mass 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.
Cross flow venting is inefficient and never appropriate for heated enclosures. Mechanical venting such as exhaust fans are only capable extraction whilst on and can never be as effective or cost efficient as an appropriate natural system.
More information on indoor pool and spa roof ventilation is available from Condor Ventilation.