By Harry Topikian
Thanks to recent technological advancements, indoor waterparks can now have perfect indoor air quality (IAQ) and green environments. However, anyone who is involved in the commercial aquatics industry knows these facilities are capable of the exact opposite—uncomfortable indoor air environments that are not energy efficient.
For example, indoor waterparks are not typical role models for IAQ and energy conservation. When these facilities started to become popular several years ago, many waterparks tended to embrace the ‘pay later’ option in controlling the tremendous humidity generated by 27.7 C (82 F) quick-evaporating pools and a myriad of aerosolizing equipment (e.g. waterslides, water cannons and waterfalls).
Instead of using specialized mechanical equipment to control humidity, the trend over the last decade has been the use of conventional equipment to provide make-up air. This equipment brings in outside air, conditions it by heating or cooling it, then wastefully exhausts it in an attempt to control relative humidity (RH) and prevent the facility from feeling like a muggy rainforest. It is considered the ‘pay later’ option because the equipment requires considerably lower up-front capital costs than mechanical dehumidification equipment. However, as conventional dehumidification methods are significantly less efficient than mechanical dehumidification equipment, operational costs alone can amount to hundreds of thousands—or even millions—of dollars more over the typical 20-year lifecycle of the equipment, thus the pay later terminology.
Not controlling the humidity load with modern dehumidification equipment can result in an uncomfortable atmosphere of 80 per cent RH or higher, which takes its toll on patrons, employees, interior design and, quite possibly, the building’s structural integrity.
Not knowing the future success of the fledgling indoor waterpark trend or the non-interest in long-term investment as a business strategy, many early indoor waterpark facilities across North America employed thrift measures throughout to avoid high up-front capital costs.
Contrarily, the ‘pay now’ option is more environmentally friendly and energy efficient. Instead of the costly process of continually bringing in fresh air, indoor air is recirculated with a reduced amount of outdoor air, which still surpasses American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards.
Instead of exhausting the inherent evaporative effects of a warm body of water, mechanical dehumidification condenses the humidity out of the air via refrigeration coils. In the recirculation process, a comfortable 50 per cent RH airstream is returned to the indoor facility. Additional environmental measures can be applied by using exhaust air (some air must be exhausted to maintain a negative air pressure and compensate for any new outdoor air that is introduced) to preheat outdoor air during wintertime operation with a ‘Smart Saver’ function. In many cases, some mechanical dehumidifier brands allow 100 per cent of the heat recovered from the refrigeration process to be used for heating the pool water. Rather than using a dedicated, fossil-fuel-powered boiler, all the facility’s water heating is free.
Due to the costs of mechanical dehumidification equipment, those with short-term (five years or less) investments in mind might be better off in taking the pay later option and pass on the future exorbitant energy costs to the next owner. However, long-term ownership can save significant energy costs, add a green facility to the local community and provide a more healthy and comfortable IAQ environment for both patrons and employees.