Swim centers are not, by nature, particularly green buildings. Heating pool water involves a substantial energy drain. Indoor facilities require substantial mechanical equipment to dehumidify and condition the air. Air quality suffers from the chlorine in the water. Nevertheless, new technologies and creative design strategies can go a long way to cutting electricity use and making these facilities healthier.
Variable-speed filter pumps are becoming more standard, enabling more control over the amount of energy required to operate the pool. A low-tech energy-saving solution is to cover the surface of the water with energy blankets during nighttime hours, when the pool is not in use. These blankets significantly reduce the loss of heat, water, and chemicals through evaporation, lowering operating costs. From a design point of view, the blankets pose a storage challenge; they take up substantial room when rolled up during the day, yet they should be placed close to the water to encourage operations staff to deploy them regularly. Generally, the goal is to provide a storage area that parallels one side of the pool for both easy deployment and storage.
Evaporation can be an even bigger issue for outdoor pools, especially in windy climates. Strong breezes can also disrupt competition by creating waves and cooling the water. Strategic placement of the locker and shower building or other structures can help block prevailing winds. When the Burgess Community Center in Menlo Park, Calif., was renovated and expanded in 2004 with the addition of three outdoor pools, they were sited carefully so that the locker room facility, administrative facility, and mechanical building shield the water from wind on two sides.
While too much wind can be a challenge for outdoor facilities, indoor facilities have the opposite problem: They require a significant amount of air movement. At the East Oakland Sports Center, which was completed in 2011 and awarded LEED Silver certification, four large fans are part of a high-efficiency mechanical system. The fans are an energy-efficient way to provide much-needed air movement, which in turn reduces the need for dehumidification operations.
Built in 2005, the Morgan Hill Recreation Center in Morgan Hill, Calif.—the first outdoor aquatics facility to receive LEED Silver certification in the nation —not only uses its affiliated structures to shield the pool from the winds on one side, but also incorporates a row of 30-foot-high cloth “wind sails” to block the prevailing winds and reduce heat and water loss due to evaporation. This low-cost windscreen is semipermeable to avoid creating turbulence on the other side. It also serves as a marker for the facility, as it is visible from the freeway.
The Burgess Community Center cuts energy costs by relying on solar thermal heaters. After pool water is pumped into the mechanical building for treatment, it is sent through pipes in the roof, where sunlight preheats the water, up to 10 degrees, before the mechanical system heats the water the rest of the way. At Morgan Hill Recreation Center, the floor slab of the shower area is equipped with a heat-recovery system that extracts heat out of drain water that would otherwise be lost, putting it to use to preheat cold water entering the building.