Energy and HVAC Challenges
One challenge with solar thermal or photovoltaic systems is that they can take up a lot of roof space, which can limit or exclude incorporation of skylights. Cogeneration systems have the benefit of not requiring roof space—they can be tucked into a small closet. They use natural gas–powered microturbines to generate electricity; the resulting waste heat is captured to heat the pool water. Cogeneration can be noisy, however, so it needs a dedicated, acoustically controlled space. And it is mainly appropriate for indoor pools, since outdoor swim facilities do not require enough electricity generation. With one 60-kilowatt micro-turbine, the San Luis Obispo Swim Center in the city of San Luis Obispo, Calif., generates almost enough electricity to power the swim center complex while also producing 500,000 Btus to warm the pool water.
The dehumidification systems for indoor swim facilities require tightly sealed environments, so natural ventilation is not usually an option, although operable windows may be useful as a backup system. Natural ventilation can be employed in ancillary structures, such as locker rooms, shower rooms, administrative offices, and atriums and other public gathering or circulation spaces. Both Burgess Community Center and Morgan Hill Recreation Center rely on this strategy.
No matter how many sustainable strategies the architectural design employs, reducing energy use relies heavily on operations. Pool mechanical systems tend to be highly complex. If operations personnel simply toss chemicals into the pool without carefully checking the balance, finishes wear down swiftly: tile loosens, concrete spalls, stainless steel begins to stain. Indoor natatoriums require the dehumidification system to run constantly, so if the system breaks down and employees don’t act quickly, the moist air can corrode a range of durable materials. Even something as simple as forgetting to place the energy blanket before closing for the night, or placing it improperly so that heat escapes, can cause energy consumption to spike.