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Creating comfortable environments in natatoriums

Using government incentives to pay for green technology

Community, YMCA and school pools have embraced the mechanical dehumidification strategy more easily because they typically have long-term missions early on. Older pools with conventional make-up air equipment are retrofitting to new technology with green and IAQ focuses.

D 4-foot-wide mechanical room access hallway could only accomodate the dehumidier in 150 pieces
The installation of the replacement dehumidification system in the Lois Hancey Aquatic Centre in Richmond Hill, Ont., took two years of planning. It was delivered to the jobsite in 150 pieces small enough to fit through narrow 1-m (3.3-ft) wide hallways (inset) and assembled in a small 70 m2 (750 sf) mechanical room.

For example, the town of Richmond Hill, Ont., primarily used make-up air equipment and recently retrofitted its HVAC system at the Lois Hancey Aquatic Centre in favour of green heat-recovery mechanical dehumidification equipment. The environmental mission has paid off handsomely with incentives and quick paybacks.

When built in 1991, the facility followed status quo natatorium design, relying on a conventional unit. It provided 7.08 m3/s (15,000 cfm) 100-per cent make-up air and used mixing dampers to control evaporation from the 650-m2 (7,000-sf) wave pool and 65-m2 (700-sf) therapy pool. The HVAC system created economizer-type conditions and saved energy by taking advantage of dry ambient air during winter months. Mechanical engineers involved with the retrofit project abandoned this method in favour of 24-7 dehumidification and energy recycling to better handle peak loads in summer months, which were characterized as uncomfortable.

This system was replaced with the current mechanical dehumidification equipment, which has a moisture-reducing capacity of 258.5 kg/hr (570 lbs/hr) and a greater capacity to recover heat for pool water heating. Its heat recovery system, which reclaims heat from exhaust air, combined with the reduction in electrical demand by using a newly-developed energy-saving multi-fan array, qualified the project for a $100,000 Cdn Municipal Eco Challenge Fund grant from Ontario’s Ministry of Energy and Infrastructure. The new system has cut annual energy costs by $76,000 and reduced maintenance costs by $30,000.

When combining the grant, operational savings and reduced maintenance costs, engineers estimate the dehumidifier’s payback at less than five years.

“We’re much greener now, but we have also improved our indoor air quality. There’s no longer a chlorine odour and humidity is now maintained at a comfortable 50 to 60 per cent year-round,” said Saroj K. Acharya, P.Eng., LEED-AP, CEM, facility systems manager, town of Richmond Hill.

Although these two examples are of an indoor waterpark and a community pool, green technology and IAQ measures can be applied to any indoor pool/spa facility, whether it’s in a residence, hotel, school, fitness club or other facility with aquatic features. It’s not opinion that conventional air conditioning can’t handle the tremendous humidity loads of a natatorium; it’s a fact backed by ASHRAE standards. Mechanical dehumidification, on the other hand, facilitates better health, IAQ, heat recovery, energy savings and environmental consciousness.


Harry Topikian Head ShotHarry Topikian, P.Eng., is vice-president, business development, Dectron Internationale, in Montreal, Que. He has 25 years experience in energy recycling and engineered air treatment solutions. Topikian is a graduate of the building engineering program of Concordia University. He can be reached via e-mail at

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