Feature Article - May/June 2006
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Undercover Operations

With proper planning, adding a pool enclosure can boost patronage and profits

By Dawn Klingensmith

Under pressure

Several types of enclosures are offered at a variety of price points. At the most affordable end of the spectrum are vinyl-coated polyester air-supported structures, commonly called domes or bubbles, which generally are put in service for winter only and stored during the warmer months. Fans inflate the structures; once in place, continuous fan operation and positive inside air pressure are required to keep them inflated. Cables attach to beams around an air dome's perimeter to anchor it. Some models have see-through sides or screened windows. To maintain air pressure, revolving doors typically are used.

The insulation values of the air dome must be sufficient to prevent condensation at the lowest expected ambient temperatures, which generally is achieved in part by using an outer membrane in conjunction with a liner. Like a ski jacket, this two-ply fabric provides air spaces that increase insulation.

In certain climates, air-supported structures cry out for mechanical heating, ventilation and cooling (HVAC) systems to combat condensation and humidity. According to one manufacturer, most of the big players in the air-supported structure industry ship the dome, the inflation system, and a heating and ventilation system "all in one box." If you need to purchase an HVAC system as an extra, though, be advised that it probably may cost more than the air dome itself, and the associated operational costs will administer repeated bottom-line bruisings.

Critics of these types of enclosures say that proper ventilation is complicated by the fact that positive air pressure is needed to keep them inflated, so air quality and comfort become issues. Mendioroz has heard complaints that air domes make for swampy, stifling environments.

Another common complaint is that air domes don't "pop up" as easily as buyers might envision. When you consider that relearning how to erect your four-man tent when camping every year can be a lesson in humility, you'll start to understand why. Most air domes take at least a day to inflate and two or more days to collapse and put away. To extend the tent comparison, if you've ever stuffed your tent in its bag after a rainy camping trip without drying it out first, you'll recall the unpleasant olfactory surprise that awaited you when you next unpacked it. So, to prevent mildew and increase the odds that an air dome actually will live out its purported 10-year life expectancy, you need to make sure it's thoroughly dry before folding and stowing.

In summary, air-supported structures should perhaps be thought of as affordable short-term solutions for pools simply aiming to stay open through the winter but may not be an ideal option for aquatics facilities looking to develop robust, year-round programming.

Right on tracks

Also at the less expensive end of the spectrum, telescopic enclosures cost more than air-supported structures but offer increased versatility. These structures usually consist of polycarbonate—or some other type of glazing—and extruded aluminum arches, each of which nests inside a slightly larger one so that the structure opens and closes like a telescope.

The system operates either by way of deck-mounted tracks, which function like sliding-door closets, or via trackless rollers. Taking safety and convenience into account, the track design probably is more suitable for nonresidential applications, as the tracks anchor the structure. Trackless models must be fastened to the ground section by section when wind is expected.

Most U.S. manufacturers of telescopic structures tend to target residential pool owners. According to one manufacture, the industry is still in its infancy, and the technology hasn't advanced to the point where large-scale commercial applications are feasible. Therefore, relatively few nonresidential pools rely on telescopic structures for respite from bad weather, but it's an industry that is worth keeping an eye on, perhaps.