Feature Article - February 2019
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Take It Year-Round

Structure Solutions to Protect Your Programs From Mother Nature

By Joseph Bush


Ozdemir said these structures are more attractive than ever as materials and construction methods have evolved. They are made from aluminum, polycarbonate or acrylic plastics, rubber and stainless steel. He said in the past the plastic was always the first to wear out; because of UV rays, it yellowed. That technology has improved to the point that, for example, where there once was a 10-year warranty and the product wouldn't last 10 years, now it's lasting much longer than 10 years, he said.

"We're always developing in terms of the technology of our connections and ability to assemble it quicker," Ozdemir said. "If you were to compare two of the exact same size structures between today's assembly methods and techniques and timing, we're doing things twice as fast as we were 10 years ago in terms of assembly and manufacturing.

"From an owner perspective, once we're ready to come and install it, there's a lot less downtime for the staff and their programs today than there might have been 10 years ago or even five years ago."

Let the Sun Shine In

Another retractable roof company based in Oakville, Ontario, Canada, covers aquatic areas for health clubs, YMCAs and natatoriums. It specializes in building for a humid environment because one of the downsides to building an indoor pool is the high maintenance due to trapped evaporating moisture and chemicals, said Dave Bolwerk, vice president of sales.

New client relationships begin with education about what humidity can do to materials.

"Pools in general are large projects, and in most cases this is the client's first experience in building a pool and therefore usually have no idea as to what it costs," Bolwerk said. "When discussing an indoor pool, clients may have some experience with building some structure in their lifetime and think they have a handle on what a building could cost, but putting a building over a pool is unlike any building they have done before."

Buildings that enclose outdoor pools for year-round use need foundations, and fire protection, lighting and dehumidification systems, Bolwerk said; they are not temporary and do not get set up every season.

Retractable skylights are another option, enabling facilities to feature as much light as possible when the roof is closed.

The design needs to result in a space people want to be in, and come back to, said Bolwerk. "People want to be outside, and swimming is an activity that is typically associated with sunshine and fresh air," he said. "It is difficult to get this 'feel' in a conventional structure. Windows can bring in natural light, but without an operable roof and operable doors and windows, a mechanical system still needs to run 24/7, which results in great cost."

During summer months the retractable roof facility is run as an outdoor venue and the HVAC system is shut off for utility cost savings, said Bolwerk. While the HVAC system is required when the roof is closed in the winter, the all-glazed nature of the building permits light and maintains the outdoor feel.

Because indoor pools cost so much operationally, in terms of air quality and maintenance, retractable technology can provide advantages, potentially using 20 percent to 30 percent less energy.

"While some may question this statement for an all-glazed building, consider the fact that the open roof and doors allow the HVAC system to be turned off in the summer, there usually is no air conditioning, and that because of the all-glazed nature of the building, there is no need for artificial light during daytime hours," said Bolwerk. "When the roof is closed in the winter, the solar gain offsets some of the heating requirements and again, during daylight hours, there is no need for lights."

Bolwerk said his company's buildings bust the myth that an all-glazed building with a retractable roof could not work because an indoor pool had to be built of all conventional material as a closed system, and the only way to combat the moist aquatic pool atmosphere is to run a dehumidification system 24/7. He said with all-aluminum and all-glazed materials, mechanical engineers have become adept at designing HVAC systems that are efficient and work to maintain a comfortable atmosphere in the winter months.

"Experience over the years has resulted in aluminum structures becoming much larger, spanning greater distances, enabling these nonconventional structures to enclose entire waterparks," he said. "Accompanying the expanded buildings is the technology in operating systems and mechanical devices to open larger panels in the roof and in some cases to move large panels sideways or skylights that retract completely off the opening and parking over the adjacent roof."

Aluminum is the key material, said Bolwerk. Any pool operator in a traditional structure can vouch for the corrosive nature of pool chemicals, which leads to regular maintenance, extensive repair time and cost. He said an all-aluminum framed building does not have these issues.

Retractable roofs require motors, and Bolwerk said these motors are part of a closed system that does not require oil or grease and so does not require mechanical maintenance. Operating system parts such as an aluminum rack and brass gear wheels are all designed with the atmosphere in mind and also require no maintenance.

While the buildings can span in excess of 185 feet, Bolwerk said the typical enclosure for a natatorium measures 100 feet to 120 feet wide and can be anywhere in length from 130 feet to 150 feet. They are occasionally longer than that depending upon number of pools being enclosed or the activities for which the enclosure is intended, such as competition and spectator viewing.

"A retractable roof enclosure is truly a unique structure that easily converts to an outdoor venue at the push of a button," Bolwerk said.