Through evaporation, indoor pools produce a large amount of chlorine-charged vapor. Proper ventilation is another important part of this indoor pool maintenance guide. If an indoor facility uses chlorine, chloramines can be released into the air. Pool facilities must have adequate ventilation to vent this air to the outside instead of in changing rooms, bathrooms, etc.
Ventilation is also used to avoid temperature stratification in installations with high ceilings. Pool operators must also use low-level return grilles to extract air from the surface of the water. As early as the late 1980s and early 1990s, many customers were convinced that residual ventilation (i.e. large exhaust fans and recovery air) could be used to control the high humidity of the indoor pool.
A ventilation system can only provide effective control of the humidity of an indoor pool when the outdoor air is reasonably drier or the same as indoor air with a lower relative humidity 365 days a year. These conditions rarely occur and the heat from the pool is literally thrown out the window (hence the name “residual ventilation”). While the initial costs may be lower, it soon becomes apparent that the operating costs of these older ventilation systems are also the highest compared to a properly designed dehumidification system. When there is a folding roof, it is recommended to ventilate with air from the pool room, ensure that it is insulated above it, ensure that a vapor barrier has been installed on the warm side of the pool room, and address negative pressure.
The ASHRAE 62.1 requires a minimum of 0.48 cubic feet per minute per square foot of water surface of the pool and pool deck, plus 7.5 cubic feet per minute per spectator in the swimming pool. The old days of entering a sports and recreational facility and feeling the strong smell that indicates the presence of a swimming pool are long gone. For a commercial HVAC contractor, designing a system for a swimming pool or building that contains a pool can be especially difficult. The wet area of the roof is defined in ASHRAE standard 62 as the area surrounding the pool and that is expected to become humid during normal use of the pool.
The first is the compressor section to comply with the evaporation rate depending on the size of the pool and spa, the temperature of the water and the activity factors inside the pool room. The Centers for Disease Control and Prevention provides extensive information on the air quality of indoor pools and the operation of public swimming facilities.