5-20
WaterSense at Work: Best Management Practices for Commercial and Institutional Facilities
5.4
Commercial Pool and Spa
Equipment
Overview
Pools and spas are found in many commercial or institutional settings, including
hotels, schools, community centers, hospitals, and apartment complexes. The size
and features of these pools vary widely depending on their intended use and set-
ting. Table 5-1, which summarizes typical pool sizes for commercial pools and spas in
California,
47
shows that a typical commercial pool can contain between 34,000 and
860,000
gallons of water. Spas are much smaller, containing on average 1,100 gal-
lons. Due to a lack of data, the California Urban Water Conservation Council (CUWCC)
document from which this data was taken assumes that the typical pool sizes esti-
mated for California are representative of pool sizes nationally.
Table 5-1. Typical Sizes for Commercial Pools and Spas
Pool Type
Area
(
square feet)
Depth
(
feet)
Volume
(
gallons)
Spa
40
3.0
1,100
Hotel (in-ground)
1,000
4.5
34,000
Public (in-ground)
4,000
5.0
150,000
Olympic (in-ground)
14,000
8.0
860,000
Overall, a large volume of water is used to fill commercial pools or spas. Much of this
water is often lost in day-to-day operation due to evaporation, leaking, and splash-
ing. Ongoing pool or spa maintenance also creates significant losses in filter cleaning
and mineral buildup control.
Because evaporation, filter cleaning, and mineral buildup control represent the great-
est uses of water for commercial pools and spas, they also provide the most significant
opportunities to achieve water savings. CUWCC estimates that water evaporation,
filter backwashing, and mineral buildup control account for 56, 23, and 21 percent
of pool water use, respectively, across all pools installed in California.
48
Water losses
from leaks and splashing are not included in this estimate because they are difficult
to quantify. Although the estimates used in this section are specific to California, EPA
assumes that, with the exception of evaporation (which is dependent upon local cli-
mate), they are applicable to and representative of pools and spas nationwide.
Evaporation
Water continually escapes pools and spas due to evaporation from the pool/spa
surface. The rate of evaporation will depend upon several factors, including: water
temperature, the pool’s ambient conditions (e.g., indoor or outdoor), the extent of
convection over the pool’s open surface, and the surface area of water that comes in
47
Koeller, John and H.W. (Bill) Hoffman & Associates, LLC. September 2010.
Evaluation of Potential Best Management Practices—Pools, Spas, and Fountains
.
Prepared
for the California Urban Water Conservation Council. Pages 3-30.
48
Ibid
.
Page 30.
