There are two potential budget-busting catastrophes looming in the mechanical rooms of indoor pool aquatics facilities throughout North America. The ongoing government R-22 refrigerant phaseout and dehumidifier replacement can potentially blind-side aquatics center managers who haven’t prepared.
The majority of HVAC systems installed during the 1980s and ’90s as well as many newer models from 2000 to 2009, operate on R-22 refrigerant. But the substance, essential to the units’ refrigeration dehumidification cycle, is unfortunately undergoing an expedited government phaseout because it is suspected of compromising the Earth’s ozone layer. Consequently, the phaseout now is creating dwindling supplies and skyrocketing prices that threaten the budget of every pre-2010 natatorium budget with an R-22-based dehumidifier.
All refrigeration coils leak at least once in their life cycle, and many leak multiple times. If a large natatorium dehumidifier loses most or all of its hundreds of pounds of refrigerant, it will cost $20,000 to $40,000 just in R-22 refrigerant replacement costs. The closer a dehumidifier edges toward its expected 20-year useful life cycle, the greater risk of a refrigerant leak.
The growing liabilities associated with R-22 may be enough impetus to replace an aging dehumidifier, even if it still works.
The other budget-busting catastrophe is the inevitable need for dehumidifier replacement. Tens of thousands of systems produced during the aforementioned hey-day probably will need to be switched out within the next five years.
Operators can budget ahead for future replacement dehumidifiers, but there may be hidden costs due to limited mechanical room access. Surprisingly, many mechanical rooms have only a double door, and many times just a 34-inch-wide pedestrian door, neither of which can accommodate a typical unit that’s the size of a 20-foot-long sea container or larger.
Consequently, there are four solutions aquatics facilities are using to replace dehumidifiers in inaccessible mechanical rooms:
1. Open an exterior wall or the roof to create access for a new unit and removal of the old. However, this can incur tens of thousands of dollars in construction costs.
2. Dismantle the existing unit, but retain the shell to house new components that must be custom-engineered, sized to fit restricted mechanical room access and installed piecemeal into the existing configuration.
3. Remove the entire old unit, then manufacture and ship a new system in sections that fit through an existing or enlarged mechanical room access.
4. Replace the existing dehumidification system with recently developed smaller modular units designed to be easily wheeled through 32-inch-wide door frames and connected quickly in tandem to equal a large unit’s dehumidification capacity.
Adlai Stevenson High School in Lincolnshire, Ill., a 3,950-student school with a huge 40,000-square-foot natatorium, had a choice between the first two options when replacing two aging HVAC dehumidifiers that were costing tens of thousands of dollars in annual maintenance costs. The removal of the 15-by-9-by-8-foot and huge 15-by-7-by-8-foot units would have cost upwards of $400,000 just in construction costs to tear open a wall or roof for access.
Instead, the school district left the units in place and commissioned a different dehumidifier maker to factory-build entirely new components, coils, piping inlet/outlet receptacles and control packages to fit inside the original manufacturer’s unique steel shell configuration (see photo on page 20).
This unusual technique may someday become a standard retrofit procedure.
The third option was chosen by the city of Kanata, Quebec, Canada for the retrofit and conversion of its 25-year-old conventional indoor pool city recreation center into the new Kanata Leisure & Fitness Centre Wave Pool — an aquatic paradise featuring a wave pool, children’s pool, water slide and spa.
KLFCWP is a classic example of mechanical dehumidifiers reaching the end of their life cycles, but the facility’s mechanical room had no access for removal or replacements.
The specification of one large 24-by-10-by-8.5-foot custom-made unit to replace two units saved KLFCWP tens of thousands of dollars of installation and labor costs and facility down-time. Engineers determined the outdoor air louver on the mechanical room’s exterior wall would provide the most economical access for getting the unit into the building. The manufacturer custom-built the unit, tested it under simulated operating conditions, and shipped it to the site designed for easy knock-down.
The mechanical contractor rigged the three sections through the outdoor air louver, which was enlarged to 9.1-by-9.8-feet for more access, then assembled and installed the dehumidifier inside the mechanical room.
Queens University, Charlotte, N.C., chose option 4 — not for a retrofit, but for its new $30 million, 144,000-square-foot Levine Center for Wellness and Recreation. The 7,500-square-foot pool’s cooling, heating and dehumidification are controlled with two piggybacked modular dehumidifiers. Originally designed for limited access retrofit work, the two modular dehumidifiers were specified because their easy field-integrated configuration occupy 38 square feet and allow more space for other activities in the building, which was built on a very confined campus plat. When their life cycles end in 20+ years, the units can be wheeled out of the 34-inch-wide pedestrian door and replaced with more modular units.
Because the integrated units each have their own fans, compressors and coils, the facility has redundancy. Automation programming can efficiently save with just one unit being left on during off-peak hours (natatorium operation requires 24/7 dehumidification). This is proven to be more efficient than running one large unit compressor.
Planning for the future
Because dehumidifier replacement is rarely a drop-in procedure, the inevitable costs of unseen variables must be planned for and budgeted.
Besides mechanical room access and other logistics, a manager can improve the facility with today’s new technology that can dramatically improve operating efficiencies and render a quicker payback than an identical replacement. Recent advancements incorporate heat recovery, web-based monitoring for pinpoint operation, highly efficient direct-drive fans and other significant energy management game changers.
Most importantly, emerging designs now are supplanting the liabilities of refrigerants such as R-22, and even successor refrigerants such as R-410A, with the environmental friendliness and decidedly more inexpensive option of glycol ethylene for heat rejection, which has no energy efficiency trade-offs.
Proper planning and incorporating today’s technology can tame those budget-busters hiding in the aquatics center mechanical room.
Ralph Kittler, P.E., is co-founder and vice president of sales and marketing at Seresco USA in Decatur, Ga., a subsidiary of natatorium dehumidifier manufacturer Seresco Technologies Inc. Kittler has 23 years’ experience in the HVAC industry and is an ASHRAE "Distinguished Lecturer."