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by Marion Hixon
Kids shoot down slides, wave machines furiously pump water, patrons drift lazily through a winding river, and warm air floats through open windows—a seemingly productive day at the waterpark. Both water and profits are flowing, but what’s happening under the surface and in the pipes matters as much as the guest experience. In this likely scenario, fans are blowing, air chillers are spinning, a digital system is differentiating the amount of outdoor air in the park, and the water pumps are keeping 100-plus guests in the lazy river moving steadily along.
Expenses for electricity, heating, and air conditioning are often a facility’s highest utility bills, and waterparks— especially indoor parks—are notorious energy users. Operators have a vested interest in maintaining a healthy atmosphere—one free of airborne and waterborne diseases— while doing so as efficiently as possible.
There are two ways to do this, says Jeff Radue, a mechanical engineer and project manager with Ramaker and Associates, a consultant firm in Sauk City, Wisconsin. “Part of the way is to remove the chloramines from the water, and the other is to optimize air handlers to remove the contaminants at the source,” he says.
Air Handling
Indoor Waterparks
 While indoor waterparks are popular attractions—particularly in cold climates—their windows and ventilation systems can pose issues, such as too much humidity in the air. “The trick in cold weather is to monitor the humidity inside and keep the air coming in from outside precisely balanced to maintain indoor air quality,” Radue says. He and Ramaker’s other consultants usually recommend a few windows be installed when building an indoor waterpark. Their team has worked with both Chaos Water Park in Eau Claire, Wisconsin, where only a few windows are installed, and Jay Peak Resort in Jay Peak, Vermont, which is completing a 33,000-square-foot indoor waterpark surrounded entirely by glass walls.
“There are some challenges, but there are also some benefits,” Radue says. “We can elect for natural ventilation, but you also want to keep air flowing across the glass surfaces to reduce the amount of condensation.”
To control humidity with the best amount of outdoor air while still recovering sensible energy (which is caused by a change in temperature), operators can use plate-type heat exchangers, which transfer heat from the exhaust air, temper the outdoor air, and push moisture outside. Heat exchangers carry a higher expense on the front end, but Radue says they pay off in the long term.
Keep It Cool
Another way to help distribute and circulate air is through the use of large fans. Indoor waterpark environments often experience stratification, where hot air rises, causing a temperature discrepancy of up to 20 degrees from the floor to the ceiling. This can cause high energy bills, uncomfortable guests, and a strain on HVAC systems. Alex Reed, marketing analyst from Big Ass Fans in Lexington, Kentucky, says installing fans at a facility will reduce the cycling time of HVAC equipment and minimize the heat loss. Industrial- sized fans also move air swiftly across the pool surface, reducing the amount of chloramines released into the air.
 Big Ass Fans’ products work alongside air handler units and exhaust fans to create a consistent exchange of inside and outside air. Meanwhile, exhaust fans, common in all indoor waterparks, help expunge stale, impure air and integrate fresh air indoors. Reed says proper air circulation should be maintained so chloramine levels do not exceed .5 PPM (parts per million). “We’ve found that indoor waterparks benefit most from the application of the fans,” he says. For example, Kalahari Resort in Wisconsin Dells, Wisconsin, saved approximately $13,000 a month on its gas bill and anticipates $100,000 in annual savings after installing fans. To start the process of evaluating or renovating an air handling system, Radue suggests operators first look at the currently functioning system: “Ask yourself what type of dehumidification system you’re using, if you’ve been having problems maintaining indoor air quality with humidity, and how well your air is distributed throughout the entire facility.”
Easy Fixes
Once an indoor waterpark is up and running with proper air-handling technology, operators quickly realize which attractions soak up the most energy, time, and staffing, as well as the park’s high and low attendance times. Kalahari features a 10,000-square-foot arcade, and officials quickly realized the resort’s electrical system could be overwhelmed if the arcade and waterpark started running at the same time. “We’re sensitive to how many occupants we have and when they’re waking up and arriving at the waterpark, so we don’t have to start everything up at the same time,” says Josef Haas, chief operating officer for Kalahari Resorts. He adds that it’s also inefficient to turn on all rides and slides at once, so those are staggered throughout the first hour of operation to alleviate pressure on the facility’s energy.
Knowing the amount of guests present can also be a good measure of how much chlorine is required for pools and how much could end up in the air. Radue says RFID systems are an effective tool for determining this factor. “There are various two-way occupancy systems that monitor who’s in and out of the waterpark,” he says. “Once we know that, we can monitor a control sequence to determine how much chlorine is needed.” This solution doubles as method for determining which rides should be running for a certain amount of people.
Disinfect at the Source
All Waterparks
Choosing a more advanced disinfection system that reduces the chloramines in and on the water is another way to keep the waterpark environment healthy and cut costs in the long run. “Integrating disinfectant systems into the process will have the side effect of aiding indoor air quality,” Radue says.
He mentions UV disinfection as a popular technique in the industry, and says there is also a rise in the use of salt-generation systems at waterparks. “These systems generate their own on-demand chlorine instead of storing bulk chlorine in tanks,” he says. “It’s lower-strength and a better disinfectant because it hasn’t been sitting around in tanks. The salt is added once chlorine is generated.” The enhanced system costs more up front than typical disinfectant systems, but also saves money over time.
Another way to remove contaminants from pools is to ventilate bodies of water with surge tanks, which capture the water displaced when guests jump into pools. “Owners who have an existing pool with a surge tank can ventilate that just a little bit, and it will improve the air quality and also reduce the amount of outdoor air needed in the waterpark,” Radue says.
Optimal Pump Performance
All Waterparks
One technique making a major difference in pump performance and the resulting consumption of energy is the integration of variable frequency drives (VFD) on this type of equipment. VFDs electronically vary the speed of the pumps bymodulating the frequency of the electricity going into them.
Radue likens the technology to an electronic remote control installed on ceiling fans—while the initial piece of equipment isn’t altered (in this case, water pumps), the energy performance can be raised and lowered when necessary.
Both the Ohio and Wisconsin Kalahari facilities use VFDs, and Haas says the integration of RFID technology aids in this incentive, as well. Operators at both facilities have seen a significant difference in pump performance once water is circulating, as the technologies don’t have to work as hard when fewer guests are present in the park.
“In the old way of doing this, we would design attractions using constant- speed pumps, which would have to be adjusted by closing a valve, but that had the effect of using a lot of energy,” Radue says.
In the past few years, enough manufacturers have begun producing VFDs to make the devices a more affordable option. “Many times, it would not be uncommon to see a 30 percent drop in energy consumption just from using the VFD,” Radue says, adding that many steps toward energy efficiency can be achieved by simply putting sensors or controls on existing technology. “You don’t have to rip up existing attractions.”
Haas says several energy-efficient decisions require a significant capital investment up front, but make money back after three to six years. Kalahari made a commitment in its capital improvement project to spend the money for the future return. “If you’re not moving toward the green initiative in your operations, you’re not being conscientious or saving money for the future,” he says. “Energy is only going to get more expensive, so we made the investment early on to reap the benefit down the line.”
 BUDGET-CONSCIOUS PUMPS:
VFDs can be integrated throughout a waterpark over time to better fit a facility’s budget. Jeff Radue with Ramaker and Associates says operators should install VFDs first on attractions which use the most energy, and suggests investigating state-run energy programs. These programs reward the use of energy conserving technologies, and sometimes grant money to companies using energy-saving methods like VFDs. |
 Electric Monitoring
Kalahari Resorts uses multiple technologies to sense a guest’s presence. Besides the RFID systems in the waterparks, room keys activate the electricity in the guest rooms, and all electrical systems—with the exception of the refrigerator— are powered down when the guest is not present.
START SMALL, SEE BIG RESULTS: Always cover your hot tubs and pools with blankets when not in use to conserve energy. |
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