Consulting engineer David Strunk, P.E., held his breath every frigid day last winter when he drove by the Pocmont Resort & Conference Center in Bushkill, PA. Once he saw that not one molecule of moisture had clouded the hotel’s new 6,000-sq-ft, all-glass, indoor swimming pool enclosure, he let out a sigh of relief.

It’s not that Strunk’s hvac design or the installation of mechanical contractor, R.J. Groner, (Stroudsburg, PA), and pool structure consultant/contractor, Omega Pool Structures, (Toms River, NJ), lacked integrity or ingenuity. And it wasn’t that Strunk’s dehumidification equipment choice wasn’t first rate because he specified a custom-manufactured dehumidification system designed especially for the space by Dectron Internationale (Roswell, GA). Instead, Strunk felt no hvac design and equipment could battle the combined elements of sub-zero weather conditions outside and the quickly-evaporating 82˚F water of a 28,000-gal pool as well as a 1,800-gal, 100˚F spa on the inside of a clear glass and metal enclosure.

“We told the Pocmont owners and the architect up front that we didn’t recommend an enclosure with this much glass because of the condensation and fogging possibilities during extremely cold days in the winter,” said Strunk, a partner at mechanical-electrical consulting engineering firm, Strunk-Albert Engineering (East Stroudsburg, PA). “We’ve designed hvac systems for several enclosed pools in the past, and this was by far the most challenging because of the amount of glass.”

Regardless of the potential condensation and fogging problems, the Pocmont’s owners and architect, Bernie Elias, The Elias Organization (Bensalem, PA), decided that the aesthetics of the beautiful enclosure far outweighed the risks. The pool enclosure, which is part of an $11 million expansion that includes a nightclub, outdoor pool renovation, gift shop, additional banquet room space, and offices, has quickly become the icon of the 52-year-old resort. Now tens of thousands of annual visitors view a panoramic scene of the Pocono Mountains regardless of the outdoor temperatures.

The Future is Now

The pool and enclosure is a peek into what state-of-the-art indoor hotel/resort pools might include in the future. The pool decking is warmed with a radiant heating system. Fashionable fabric ductwork distributes ventilation. Plus the enclosure gives the family-owned resort a five-star identity as it gleams in daytime sunlight and glows at night with architectural lighting.

The enclosure replaces a former 40-year-old, 20- by 50-ft pool and steel and plaster enclosure that suffered from humidity, chemical odor build-up, and a general discomfort level because its technology had become outdated. “The old pool was like walking through the Brazilian rainforest, whereas the new indoor pool is very dry and comfortable,” said Greg Artzt, president of Pocmont Resort & Conference Center. “Plus, it’s so much nicer in aesthetics and in bottom-line operating costs, such as maintenance and energy use.”

Although aesthetics are important, the true success of the project rests in Strunk’s air distribution design and the dehumidification work of Dectron’s Dry-O-Tron® model DS-060, which keeps the indoor pool environment at 50% rh via a 53 lb/hr of moisture-removing capacity. Exterior windows in indoor pool enclosures are a design concern because they get cold if the warm supply air does not properly blow against them. A cold window will condense moisture (much like a can of soda in summer), regardless of the humidity levels in the space.

Besides dehumidification, another strategy against condensation is Open Air’s thermally-broken enclosure design where all mullions include a rubber gasket that separates exterior and interior aluminum. “Everybody was worried about condensation except for us,” recalls Jeff Bova, staff architect for Omega Pool Structures. “With good dehumidification and air distribution, our past installations that feature the thermally broken enclosure designs of Open Air have historically stayed clear even in the coldest of climates.”

Conquering Condensation

For the expansion’s mechanical and service contractor, R.J. Groner, the pool enclosure portion of the project was fairly easy with the exception of its first experiences with fabric ductwork. The ductwork arrived in a few cardboard boxes via United Parcel Service. Preparation amounted to unpacking the boxes and screwing a track into the enclosure’s 25-ft-high top mullion. Installation took just a few hours of inserting duct supports into the track and zippering connecting sections together, according to Michael Katz, president, R.J. Groner. There were no cleats, hammers, snips, or heavy labor generally associated with traditional sheet metal ductwork.

“It was our first experience with fabric ductwork and we liked the technology very much,” said Katz, who had more challenges with the other portions of the expansion that included lifting 26 Trane Company, (LaCrosse, WI, dx rooftop units into place and running conventional ductwork. “The specification of fabric ductwork probably saved the owner over 50% in air distribution labor and material costs.” The challenge in the air distribution was not so much the amount of glass, but the many structural aluminum mullions that protrude an approximately 4 in. out from the glass surface and either interrupt air flow or create eddy effects, according to Strunk. The solution is the fabric ductwork’s two diffuser channels that were factory installed and positioned in such a way to bathe each plane of the glass roof with dry, conditioned air.

The Pocmont is probably one of the first fabric ductwork applications for an enclosed swimming pool in North America, according to Jon Flem, vice president for distribution at the manufacturer’s representative firm, The Metz Co. (Easton, PA), which represents fabric ductwork manufacturer, Fabric Air.

The Supporting Players

Besides overhead air distribution, the space also has an under-deck, PVC-coated steel ductwork that distributes air at the floor level to blanket the structure’s glass walls.

The hvac design also includes an in-deck radiant floor system manufactured by IPEX, (Englewood, CO) that’s supplied by a Weil-McLain (Michigan City, IN), 2- MMBtu liquid propane-fired boiler.

South Jersey Concrete (Howell, NJ) built the 20- by 50-ft gunite pool and it features filters and pumps by Pac-Fab (Sanford, NC). Now with the real dehumidification test of a Pocono Mountain winter behind them, engineers, architects, contractors, and owners can all rest assured that a daring trek into an aesthetic design performs as well as it looks. “Ideally from an engineering standpoint I’d prefer an enclosure with R-30 walls, two vapor barriers, and no glass at all,” quipped Strunk, “but that wouldn’t look as beautiful as this structure does.”