Kanata retrofits its wave pool
The $500,000 renovation of a 25-year-old conventional indoor public recreation centre in Ottawa—now called the Kanata Leisure and Fitness Centre—is a good example of the challenges indoor pool facilities face when fitting new equipment into original mechanical rooms.
The facility’s mechanical room had limited access; there were no shipping doors or adjacent space for expansion, yet the replacement system had to be larger due to the following factors:
- it was a single unit replacing two units;
- it incorporated more technologies such as heat recovery from exhaust and air conditioning, which the previous system did not have; and
- it had more dehumidification capacity because the original units struggled at times to accommodate the evaporative rates produced by the facility’s unique array of water features.
To meet this challenge, a larger 2.6-m (8.5-ft) high x 3-m (10-ft) wide x 7.3-m (24-ft) long custom-manufactured HVAC system was specified to save the facility thousands of dollars with respect to installation and labour costs, not to mention facility downtime. After scouting the site, engineers determined an outdoor air louver, part of a large mezzanine-level mechanical room’s exterior wall, would provide the most economical access point to get the system into the building. The manufacturer also custom-built the unit for disassembly into three, 2.4-m (8-ft) long sections for shipping, but only after the factory assembled and tested the unit under simulated natatorium operating conditions. The mechanical contractor on the project rigged the HVAC system’s three sections through the outdoor air louver, which was expanded by 2.7 x 3 m (9.1 x 9.8 ft) to provide additional space, then reassembled and installed inside the small mechanical room. The expanded louver opening was then refitted for a new outdoor air damper/louver. While reconfiguring walls or roofs can add
expense to a retrofit, the enlarged access was beneficial for complying with American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard-62 outdoor air rates, which have increased since the facility was originally constructed in 1986.
Building a ship in a bottle
There has been an influx of indoor pool facilities with HVAC equipment (circa 1980s) in need of replacement over the last few years. Some of these facilities have also proved challenging due to the mechanical room’s size limitations, location, or accessibility.
One difficult retrofit completed by a Mississauga, Ont., manufacturer’s representative/contractor was a 30-year-old, 279-m2 (3000-sf), suburban Toronto municipal pool with an aged dehumidifier located in a second floor concrete bunker with no external access doors. Making matters worse was a 15-step access stairwell that leads to the mechanical room’s 863-mm (34-in.) wide pedestrian door.
One option was cutting into the building’s roof and the mechanical room’s ceiling to accommodate a drop in placement of the 1.8-m (6-ft) high x 1.8-m (6-ft) wide x 4.8-m (16-ft) long unit with a crane. The job estimate for opening and closing the access holes was $40,000, which the city declined. Another option was putting the new unit on the roof; however, that would require another budget-busting process that would have included structural roof support reinforcement, connecting ductwork, new utility runs, and an improved roof access for future maintenance.
The chosen alternative was disassembling the unit at the manufacturer’s factory and shipping it in five pieces. Once on-site, the five sections were further broken-down to reduce weight and make it possible to fit the sections through the narrow door and stairway. Once inside the mechanical room, the sections were reassembled.
As per the recommendation of the project’s consulting engineer, the contractor worked with the manufacturer to pre-plan site condition limitations, turning radiuses, duct connections, obstructions, piping connections, and other variables the firm anticipated based on similar challenges the company experienced in the past. Co-ordination with manufacturers is important, because not all companies will accept the engineering restraints required with units planned for disassembly and reassembly on-site.
The same contractor also tackled another challenging project, but with a considerably larger dehumidifier unit that was 3.3-m (11-ft) high x 3-m (10-ft) wide x 10-m (33-ft) long. This system—designed for a Toronto suburb jobsite—was to replace an HVAC system installed during the 1990s. To complete this project, the unit was delivered in 150 sequentially-numbered and identified pieces to fit through the 2415-m2 (26,000-sf) facility’s 1016-mm (40-in.) wide hallway that led to a restricted 70-m2 (750-sf) mechanical room.
Typically, the manufacturer would assemble a conventional dehumidifier with welds; however, this project’s many sections were engineered to be bolted together on-site. The contractor then set-up the mechanical room like a mini-factory, complete with chain lifts for positioning heavy components in place and welding stations. Assembly required staging six technicians, each working 12 hours per day on their own specialty in frame/enclosures, piping, and electrical.
