Natatorium Dehumidifiers Reduce Costs

COLUMBIA, Mo.— Visitors at the new $49 million Rothwell-Brewer Student Recreation Center [see FOM, Back to School 2005] are usually impressed by Missouri’s largest aquatic complex.

But behind-the-scenes energy savings designed by the complex’s design team will help the University of Missouri to reduce operating costs over the life of the center’s dual natatoriums. The team of architects, consultants, and engineers consisted of consulting engineering firm McClure Engineering Associates, St. Louis ; architect Hastings +Chivetta Architects Inc., St. Louis ; commercial pool consultant Councilman/Hunsaker Associates, St. Louis ; and mechanical contractor J. Louis Crum, Columbia , Mo.

Instead of accepting a conventional economizer to take advantage of approximately 1,500 hours of cooler outside air during the spring and fall seasons, for example, McClure specified energy saving configurations in each of the five commercial dehumidifiers supplying the competition pool and leisure pool natatoriums.

The custom-manufactured equipment configuration by indoor air quality manufacturer Dectron Inc., Roswell , Ga. , places 4,100-cfm (minimum code) and 22,900-cfm (purge) exhaust fans before the evaporator coil, and relies solely on the supply air fan to re-circulate natatorium air during unoccupied hours at a significantly reduced energy rate. The minimum exhaust fan operates only during occupied periods as opposed to a conventional economizer, which operates a full-size return fan in conjunction with the 24/7 supply fan. McClure’s configuration specification is capable of introducing 100 percent outside air to purge the space effectively during super-chlorination periods. Splitting the two exhaust fans makes each dehumidifier more efficient, with both net sensible cooling and fan operation.

Equally innovative is Hastings+Chivetta’s architectural design of the 37,800-square-foot natatorium — the larger of the two separate natatoriums in the five-phase project, which included the expansion, renovation and restoration of the neighboring 100-year-old Rothwell Gymnasium and 76-year-old Brewer Fieldhouse. Hastings+Chivetta designed the competition area with a 50-meter pool, 10-meter diving well and 1,000-seat spectator area inside the addition to the fieldhouse.

All air distribution is from ceiling-hung ductwork because the preferred method of adding under-deck air distribution was physically impossible in both the Rothwell and Brewer buildings retrofits because of existing foundations.

The Rothwell-Brewer project is the largest recreation project in the history of Missouri higher education.