Natatoria are complex aquatic environments that require specialized expertise and careful consideration by design teams developing optimal heating, ventilation and air conditioning (HVAC) solutions.  Every aquatic center is unique, and every unique component has the potential to directly impact the delicate air and water quality balance.

According to an article published by ByDesign1, researchers found that “The number, types and designs of spray devices found in aquatic facilities play a significant role in illness. A facility may have one or more bubblers, fan sprays, fountains, geysers, hot tubs/spas, slides/flumes, wall spouts or waterfalls.  Aerosolization of water droplets and mist from these devices and patron splashing is often captured by the HVAC system and recirculated into the facility’s enclosed environment ….”

In most natatorium designs, space and water must strike a comfortable balance to optimize air circulation and minimize evaporation.

-Scott Hanken, Willdan Project Manager

The study found that compared to the background levels in air, fountains and waterfalls, spray devices result in a 1.4-fold increase in respirable aerosol particles.  Add a slide or flume and a 2.3-fold increase occurs. Multiple spray devices can result in a 5.2-fold increase in respirable particle levels and an 8-fold or greater increase in endotoxin levels.

Willdan engineers analyze the aquatic environment and existing equipment configurations and the roles they play as potential contributors to water and air quality. At the North Clackamas Aquatic Park in Portland, Oregon—an interactive water play adventure that features a 400,000-gallon wave swimming pool, 3 water slides, a 29-foot rock climbing wall, a toddler splash zone, a six-lane lap pool, and a 13-foot diving well—Willdan developed a contract to provide new equipment that resulted in $56,000 annual savings in utility costs.

“In most natatorium designs, space and water must strike a comfortable balance to optimize air circulation and minimize evaporation,” says Scott Hanken, Willdan Project Manager. “Willdan modified the supply air and return air systems for improved air distribution, relocated supply fans, and replaced the heat wheel with new media sized for an optimized system. Our staff also provided return air capability, automatically varying the amount of ventilation air (and total airflow), as needed, to maintain comfort and minimize energy use.”

According to Hanken, “The upgrades have allowed the owner of North Clackamas Aquatic Park to cut energy and operating costs while improving the quality of its aquatic park and maintenance practices environments.”  In the first year, the park saved more than $56,000 in energy-related costs. Annual energy consumption was reduced by approximately 297,675 kilowatt-hours and 37,387 therms, decreasing utility bills by more than 20 percent.

1 Maria Bella, AFOL, CPOI, Dale J. Cagwin, P.E., and Ronald Schaible, P.E., CSP, CIH, ByDesign, Technical Publication of the Engineering Practice Specialty, Vol. 7, No. 2, American Society of Safety Engineers.