© 2017 PoolPak LLC. All rights reserved. MPK Series - Installation, Operation and Maintenance | 9
PoolPak
®
MPK Series IOM
Indoor Air Quality
Pools and water parks with water features have a higher evaporation rate than a standard pool because of the
increased water surface area. Chloramines (See Pool Water Chemistry on the next page), which are present in
the water, become more concentrated in the air as the “water to air” interactions increase, affecting the indoor
air quality. A strong “chlorine” odor is an indicator of poor pool water chemistry, and is generally offensive to the
occupants. Higher levels of chloramines can cause skin/eye irritation and respiratory problems commonly known
as “lifeguard lung”. Most poolrooms are designed with a minimum ventilation rate to dilute the airborne pollutants
generated from the chemical interactions in the pool water. Typically these rates are based on ASHRAE standard
62.1 and dictated by local codes at about 0.5 CFM per square foot of pool and deck area, but depending on the
pool water chemistry the ventilation rate may not always be adequate for good poolroom indoor air quality.
However, increasing ventilation rates can significantly add to the cost of operation. Energy conservation strategies,
such as heat recovery, airflow measurement, and CO2 based ventilation control help control costs while improving
indoor air quality. Depending on the geographic location and season of the year, treating the outside air has a
direct effect on energy consumption. Some facilities prefer higher than minimum ventilation rates, up to 100% of
OA, to maximize indoor air quality, but the cost of treating this air can be significant.
Occupant Comfort
Occupant comfort in a natatorium is easy to understand. If you ever swam in an outdoor pool on a cold, windy day
or exited a pool in a dry, desert location you will probably notice an immediate chill. The opposite is true where
high humidity is not adequately controlled either through ventilation or by mechanical means. The moisture level
can reach such a state where it is oppressive or stuffy. Common complaints are difficulty in breathing and the room
being perceived to be warmer than the actual dry bulb temperature would suggest.
Regardless of the source of discomfort, users will not enjoy the facility if water/air temperatures and humidity
levels are not within a narrow range. Ideal water temperature is around 82°F with the air temperature about 2°F
higher to prevent chilling when exiting the pool and to minimize evaporation from the pool surface. Here are some
recommended temperatures for poolrooms, which can be adjusted to meet specific needs of bathers. In general,
“active” poolrooms are maintained at lower temperature ranges so the users don’t overheat, warmer temperatures
are more common for seniors or children or less active pools.
The desirable humidity range is generally between 50 and 60% (see Table 1-1). Greater than 60% creates a sticky
feeling and/or difficult breathing. Low humidity results in evaporative cooling on the bather’s skin, resulting in a chill.
Poor air movement caused by improper duct placement within the poolroom will also lead to occupant discomfort.
Excessive supply air blowing on bathers can create drafts, while uneven air distribution may create stagnant zones
within the space.
POOL TYPE WATER TEMP (°F) AIR TEMP (°F) ROOM RH %
Recreational Pool 80 to 85 Water Temp + 2 55 to 60
Therapy Pool 86 to 92 86
1
55 to 60
Whirlpools 99 to 104 86
1
55 to 60
Table 1-1. Typical Pool Water & Air Temperature Set-Points
1
Normally max 86°F to minimize overheating of occupants
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