Using retrofits to reduce operational costs
Existing indoor pool HVAC systems do not have to permanently breakdown before considering replacement. Long before its useful lifecycle is over, an HVAC system may show signs of inefficiency or excessive maintenance costs.
Inefficiency can often be overlooked because it is typically a slow degradation that goes unnoticed between service calls. However, comparing same-month utility bills may help spot systems that are not working up to their expected efficiencies. Indoor air quality (IAQ) deficiencies may also gradually degrade unnoticed.
Numerous maintenance or service calls throughout the year could also be a red flag for replacement consideration as well as refrigerant leaks. Leaks can be lethal to budgets, especially systems using R-22 refrigerant. This refrigerant was a popular choice in the 1980s and 1990s, which has dramatically escalated in price due to a recent production ban by government agencies. Taking this into consideration, replacing an older unit that is leaking or breaking down two or three times per year might deliver a fairly short payback via reduced repair costs and increased efficiency.
A recent development, which reduces the amount of refrigerant used by today’s newer HVAC systems by as much as 85 per cent, is another advantage manufacturers have provided to indoor pool operators against the environmental impact and cost liabilities of using banned refrigerants. The use of glycol in some of the largest parts of the dehumidifier reduces its dependency on refrigerants. Glycol has been used in this manner in other markets for decades. It is 90 to 95 per cent cheaper and more environmentally friendly than hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants.
Another consideration may be the need to replace the refrigeration piping, which is typical in split system designs where hot gas refrigerant is piped to outdoor condensers for heat rejection. New refrigerants can operate at double the pressure of what they are replacing. Consequently, existing piping is not typically suitable for reuse and should be replaced in a retrofit project. When glycol is used to reject heat generated by the system outdoors to dry coolers, polyvinyl chloride (PVC) piping—rather than copper— is used and most of the system fill comes from the water tap with some glycol mixed in.
Some ductwork modifications connecting the replacement unit to the natatorium’s existing air distribution network will likely be required; however, the majority of the air distribution system can be reused if it previously provided adequate IAQ and is still in decent shape. Additional power might be required if the original design’s operating conditions have been changed, or if more water features have been added, which increases the dehumidifier’s humidity load.
There are hundreds of indoor pool systems in Canada that could benefit from an HVAC upgrade. While indoor pool operators may look at a dehumidifier or ventilation system retrofit as an overwhelming and costly ordeal, the right team could deliver the best possible resolution with minimum disruptions and a quick turnaround. Once the upgrade is complete, the facility should benefit from better IAQ and comfort, while also operate more efficiently. Not only does this translate into reduced energy and maintenance costs, but also increased revenue from more attendance.
Ralph Kittler, P.Eng., is co-founder and vice-president of sales and marketing of Seresco USA in Decatur, Ga., a subsidiary of Seresco Technologies Inc., an Ottawa-based manufacturer of natatorium dehumidifiers and outdoor air ventilation only systems (OAVOS). He has 25 years of experience in the heating, ventilation, and air conditioning (HVAC) industry and a degree in mechanical engineering from Lakehead University in Thunder Bay, Ont. Kittler recently produced a free ‘Professional Development Hour’ (PDH) video available at www.serescodehumidifiers.com, which targets the continuing education requirements for engineers, but also serves as an invaluable primer of indoor pool design and operation basics for facility managers. He can be reached via e-mail at ralphkitter@serescodehumidifiers.com.
