Achieving LEED Platinum certification from the U.S. Green Building Council (USGBC) for a natatorium requires a dedicated team that thinks creatively and seizes every opportunity.
The East Portland Community Center aquatics addition in Oregon is a model for this certification. The new construction added a 22,000-square-foot natatorium to an existing community center to create a full-service complex.
However, the project didn’t begin with the goal to achieve any level of LEED certification. In 2004 the city hired SERA Architects, a firm that specializes in parks and recreation facilities. However, as with many government projects, before it could begin–it was put on hold.
In the meantime, the city instituted a Green Building Policy in 2006 for new construction to meet LEED Gold certification. By 2007, the aquatics project was resurrected, and construction began with changes to meet the requirements for the certification.
“The team embraced the idea and wanted to exceed the policy of LEED Gold,” says Lisa Petterson, SERA’s project architect for the aquatics addition.
The addition features a family-oriented leisure pool with a water slide, current channel, warm-water lap lanes and play features; a lap pool with four 25-yard lanes; a whirlpool; locker rooms; event rooms and all the trappings to go with it.
But the most stunning feature of the natatorium isn’t the amenities–the facility operates on just 25 percent of the energy a typical natatorium requires. This results in an annual savings of more than 60 percent, or $54,000.
Project leaders scrutinized each LEED category, and maximized the LEED rating points using innovative problem-solving.
With 120,000 gallons in the leisure pool and 90,000 gallons in the lap pool, a lot of water is there to circulate, filter, sanitize, and heat. Using a traditional sand-filter system would have resulted in thousands of gallons of water waste from the required backwashing.
Using this method also would have forced the construction and maintenance of a settling tank where water would be held until it could be used again. The sand system also requires cleaning two to three times per week, wasting not only water but also valuable manpower.
“We were in an area where the sewer pipes are small and couldn’t handle the backwash flow. We would have had to create a 10,000- to 15,000-gallon holding tank,” says Petterson. “We decided to utilize the Defender filter system that uses diatomaceous earth. The system is cleaned once every two weeks, and uses less water. This saves us over a million gallons annually.” The leisure pool, for example, only uses 750 gallons to backwash the diatomaceous earth. A Defender system also is employed on the lap pool.
An ultraviolet sanitization (UV) system is the primary sanitization for all three pools. The UV system helps to reduce the quantity of chlorine required.
The Water-Vapor Battle
Since natatoriums are notorious when water vapor creeps into the crevices and creates rot and corrosion problems, dehumidification is important to reduce the chloramines level in the air.
Therefore, building materials and equipment need to withstand these less-than-favorable conditions. “On the steel, we used a three-coating system that protects the steel from rusting,” says Petterson. “The steel is galvanized and then treated with a coating that is baked on.” Any nicks in the finish are treated in the field; this helps guard the steel from corrosion.
While the air inside a natatorium is typically maintained at 84 degrees F for favorable air quality, the air still needs to be exchanged with fresh air from outside. “Natatoriums are known for having a lot of air exchanges to eliminate the chloramines,” says Petterson. “We wanted to capture the heat from the exhausting air and reuse it. The result is a HVAC heat-recovery system that is helping to pre-heat the pool water.” On the same system is heat recovered from the mechanical room, which is then used to heat the pool water.
More Than A Window
Another part of the natatorium’s LEED rating points is in the amount of daylighting, which includes not only natural light, but views of nature without direct sunlight heating the building and producing glare. “We built a scale model of the building, and put it into the Energy Studies in Buildings Laboratory’s artificial sky, which allows us to test the lighting conditions inside of the model with sensors,” says Petterson. “We used the model to determine the apertures and shading as well as to make sure we didn’t have any direct sun penetration.” The testing also allowed the architects’ team to establish how much energy could be saved by turning lights on and off.
For sun glare, created when there is a dramatic difference between the shaded area and the lit area, a combination of shading and planted evergreens was used to decrease the contrast. Three different types of windows were used depending on the location and the necessary requirements for U-value (heat transfer unit of measure), visual transmission and shading.
The roof was designed specifically to optimize solar-energy collection. For example, an 87-kilowatt photovoltaic array covering 5,500 square feet is located on the south-facing roof. The array provides 17 percent of the energy needed to operate the natatorium. Additionally, a solar-thermal array provides hot water for the showers, saving an estimated $7,200 annually.
The solar array was possible through a third party. Commercial Solar Ventures purchased the solar panels, receives the tax credits, and owns the system for seven years. At the end of the term, the East Portland Community Center has the option to buy the solar array. “The various conservation strategies, such as daylighting, heat recovery, filtration system, low-flow plumbing fixtures and metered shower use helped get us to the Gold level,” says Petterson. “The third-party solar array was the item that put us into Platinum.”
If you are placing RFPs for new construction, lead the way to sustainable buildings by requiring they meet a specific LEED-certification level. You might just get more than you asked for in return.
Tammy York is the owner of LandShark Communications LLC, which specializes in media and public relations for outdoor recreation businesses. Her book, 60 Hikes Within 60 Miles: Cincinnati, is available online and in bookstores. You can reach her at firstname.lastname@example.org.