Operating an indoor waterpark is a lesson in efficiency. The bulk of a waterpark’s operating expenditures generally fall into the category of energy consumption, and bringing the outdoors inside requires detailed planning, a hefty investment and continued maintenance.
Being located in Anchorage, Alaska, we faced a particularly unique challenge in trying to reduce energy costs for our 40,500-square-foot waterpark, H20asis. How could we maintain 84 degrees Fahrenheit within our 54-foot-high facility, with year-round exterior temperatures ranging from negative 10 degrees to 75 degrees, without breaking the bank?
In our case, the key was solving the question of how to reduce stratification. Heated air from a forced air system (100 degrees to 125 degrees) is less dense than the ambient air (65 degrees to 75 degrees), and naturally rises to the ceiling. As a result, our heaters worked overtime to stack heat to even out the temperatures. The extra fuel required to maintain a comfortable temperature at the occupant level results in wasted energy because much of the heat stacked at the ceiling level eventually escapes through the roof.
For that reason, large energy bills and excess humidity prompted us to seek a way to keep the heat off the ceiling and return it to the pool level. The goal was saving money while staying within regulations. According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers — better known as ASHRAE — room air temperature must be at minimum 2 degrees warmer than the water to keep condensation in check. (Air, if cooler than pool water, will cause condensation and “misting.”)
Investing a large sum into expanding the ventilation system was not an option, so we needed to find something that would incorporate air movement into the facility to provide the necessary air circulation to help destratify the air in the space.
After some consideration, we settled on a system of specially designed large ceiling fans. Heat rises and collects at the ceiling level, and some of it will “escape” through the roof if it’s not well insulated. Often small ceiling fan models are run in reverse because they aren’t designed to effectively move air at low speeds.
The strategy is to pull the air up to the ceiling and down the walls. However, this can increase heat loss through the roof and doesn’t always get the heat down to the occupants in really tall spaces. The large fans we selected are designed to move air effectively at low speeds. At 15- to 25 percent of its max speed, our fans will push the heat down without creating a perceptible draft.
Even though the thermostat set point remains the same, the heating system does not have to work as hard to maintain the given set point. The energy savings achieved from reducing the amount of heat escaping through the roof is similar to turning the thermostat down three to five degrees. Since installing the fans, we’ve seen savings of more than $40,000.
What’s more, we’ve also improved our humidity and air quality control. The large-diameter fans ensure fresh air reaches the occupant level with steady, constant circulation. Regardless of the air exchange method you use, it’s important to keep air flowing around the water to help reduce condensation and help disperse chloramines.
Ultimately, by installing the fans we tapped into a growing trend in sustainable energy practices to save money and curtail energy consumption. And we found that the practice of researching and installing any number of sustainable devices is crucial to the success of waterpark facilities like ours. It goes a long way in reducing energy costs, creating a successful business model for our growing industry.