Poor indoor air quality makes swimmers and lifeguards sick, plain and simple. Sadly, this is well documented and the bane of competitive swimming and the indoor pool industry in general. Temperature and relative humidity play a critical role in human comfort levels. It is essential that both are controlled and stable. While temperature control is generally well understood and mastered by designers, it is important to recognize the special temperature levels that natatorium patrons expect. The space temperatures in a natatorium are unique to each project and assumptions must never be made. Proper control of relative humidity levels is also a concern because of the direct effect on human comfort and health. Figure 1 demonstrates that relative humidity levels outside the optimum zone 40-60% range can result in human vulnerability to disease. These diseases include bacteria, viruses, fungi, mites, and other contaminants that lower air quality and will potentially lead to respiratory issues.
While 40% is certainly an acceptable indoor relative humidity level, most indoor pools do not operate at lower than 50% RH due to significantly increased operating costs.
The type of facility being designed will typically dictate the space temperature. Table 1 helps target some typical conditions. It is critical to understand who will be using the facility in order to deliver the conditions most likely to satisfy them.
|Pool Type||Air Temperature (°F)||Water Temperature (°F)|
|Competition||75 to 85||76 to 82|
|Diving||80 to 85||84 to 88|
|Elderly Swimmers||84 to 85||85 to 90|
|Hotel||82 to 85||82 to 86|
|Physical Therapy||80 to 85||90 to 95|
|Recreational||82 to 85||80 to 84|
|Whirlpool/Spa||80 to 85||102 to 104|
|Kids Swim Schools||86 to 92||88 to 92|
Discuss the planned operation of the facility with the operator to establish operating temperatures and general expectations.