Evaporate all you want, we’ll remove more
However, without a state-of-the-art hvac system for the Tremblant’s $4 million AquaClub La Source (owned by IntraWest Corp., Vancouver, B.C.), the vast, 150 linear ft of windows revealing the picturesque scene would be covered with a blur of surface condensation.
With the combined evaporative effects of not only a 2,800-sq-ft, free-form pool, but also a 205-sq-ft spa, 738-sq-ft waterslide pool, and a waterfall in this indoor aqua park, calculating the moisture removal was no easy task for consulting-engineering firm Expert Conseil G. L’ecuyer Daoust Inc., Montreal.
Keeping condensate at bayTo keep the windows clear and the space’s relative humidity at 50%, Expert Conseil L’ecuyer Daoust specified a “Dry-O-Tron” Model DS-150 dehumidifier that removes 145 lb of moisture/hr.
The unit also heats the swimming pool and waterslide pool with recovered heat.
The firm’s design, which was installed by sheet metal contractor Ventilex Inc., Boisbriand, Que., calls for a 36-in.-round, under-deck supply duct that reduces to 26 in. with takeoffs that supply E.H. Price Industries’, Louisville, Ky., 72- by 3-in. linear supply grilles.
The dehumidification system supplies dry, conditioned air along the windows via these grilles, to eliminate condensation and retain a clear view of the outdoor pool/spa and mountainous background.
Supply air is also distributed overhead from a 16-in.-round decorative duct that feeds a supply loop in the middle of the room near the ceiling.
The search for an evaporative rateCalculating the evaporative rates was no easy task.
Assisted by manufacturer’s representative Michel Beaulieu, partner at Techno-Economique, Montreal, Daoust took the total surface area of the vessels and used the “Evaporation Rate Formula” recommended by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) to achieve a calculated rate.
These calculations are based on expected air temperature, water temperatures, and an “activity factor,” which relates to an expected occupancy.
Equally as important as the humidity control is the space’s indoor air quality. Using outside air as determined by ASHRAE guidelines, Daoust’s design calls for approximately 4,000 cfm of outside air induction when the pool is occupied.
To save energy, outside air dampers are closed automatically during hours when the pool is closed. To save further operating costs, Daoust specified an economizer function that increases outside air when cooling is required.
Other equipment specified in the new addition includes four York International Corp. 5-ton, split-system condensing units, and one Reznor Model HEEDU-350 and three Model HEEDU-300 duct heaters for space heating.