Aquatics: Cost Calculators

The First Step to Reducing Operating Costs

Every year, facility managers sit down to review their operating costs, and every year there is a huge figure that never seems to shrink: electricity. So much equipment uses electricity, and trying to simply "turn off the lights" doesn't seem to help. Everyone realizes that an aquatic facility's pump room is a big consumer of electricity, so it's a logical place to start when looking to reduce operating expenses. Luckily, there are now "cost calculators" in the marketplace that allow a facility manager to get details about where exactly that electricity is being used in the pump room. Many pool professionals use the figures they generate from these cost calculators as the basis for presenting the need to upgrade to more efficient equipment or add a variable frequency drive, and also to show prospective savings capabilities to an electric company to be approved for possible rebates for using more energy-efficient products or VFDs. Knowing the potential savings that will come from upgrading equipment is the first step in renovating an aquatic facility's pump room. When an aquatic facility sees that it can save from $300 to $1,000 a year in electricity, it becomes much easier to decide there is a need to upgrade pump room equipment.

What Is the Cost Calculator?


As the name implies, cost calculators are set up to calculate the cost of electricity by one particular piece of pump room equipment. Pumps are a great place to start because they are big electricity users. The calculator will start by asking questions about the facility—so be ready with how many gallons of water are in the pool and the turnover time of the pump. Calculators will also ask if there is a minimum required flow rate and the number of days the facility is open per year, and how long per day the facility is open and equipment runs. Be sure to have an electric bill handy to enter the cost per kWh of electricity and the horsepower of your existing pump. Calculators will even take into consideration the suction and return pipe size and the estimated flow rate. With this information the cost calculator can quickly identify power demand and energy use per day and more importantly, the cost by year. Comparing the figures of current equipment to the electricity usage figures of a new, energy-efficient pump puts the savings figures in black and white.

Commercial Aquatic Facilities & Utilities

The news continues to point out that the U.S. electrical grid is stressed. With an aging infrastructure and constrained capacity, utility providers are looking for ways to get rapid reductions in the amount of power they need to provide. With more than 322,000 commercial aquatic facilities in the United States, pumping 70 billion gallons of water, utilities are looking at commercial aquatic pump rooms as an area where they can get quick reductions in power demand. If you assume an average figure of $0.0583 per kW with a 7.63 HP per every 100,000 gallons of water, a 20 percent speed reduction for one hour would free up four medium-sized power plants. If you reduced the pump speed by 50 percent for 1 hour, aquatic facility pump rooms would free up seven medium-sized power plants.

CPS Energy, a local utility provider in San Antonio, Texas, is an example of a utility looking for quick reductions in power usage. Texas has one of the largest installed number of commercial pools in the nation with well over 30,000 installed pools as of 2012. The City of San Antonio worked with CPS Energy to reduce the city's energy usage. After doing an initial energy audit of the city, using tools similar to those of a typical cost calculator, the city determined that by retrofitting 22 city-owned pools, the utility would experience a dramatic reduction in energy demand and the city would get a payback on the project in less than one year! The 22 city pools primarily worked to reduce the speed of their pumps. They did this by replacing older pumps and installing variable frequency drives. The total project cost, for equipment and labor, was $137,000. However the annual electrical savings was $63,000, and CPS gave the city of San Antonio a rebate of $87,000. This gave the city a payback on the project of just nine months and a five-year return on investment (ROI) of 530 percent.

Using the Cost Calculator for Proposals

Using the cost calculator is the first step in getting an aquatic facility to consider upgrading or retrofitting its pump room. It's an easy tool to close a deal with a facility that might be hesitant to upgrade equipment. When you can go from a $1,000 power bill in one year to $300 after upgrades, it's a real no-brainer. Then the question becomes, what will the facility do with that extra money? Programs? Other?

The city of London, Ontario, Canada, had a similar experience to that of San Antonio. Several years ago, the entire city hired an auditor to do a cost-benefit analysis of reducing energy consumption on all city-run facilities that included six municipal pools. The calculations were powerful enough that the city undertook retrofitting a myriad of systems to lower energy consumption. This included installing VFDs on all the pumps of all the municipal pools in the city.


Hollandia Pools was the company that won the bid to do the swimming pool pump retrofits. The city put VFD units on all their swimming pool pumps, and they also installed UV with the intention of reducing the overall "consumption" footprint on the planet as UV reduces chemical usage.

"Not only did they want to reduce their energy consumption, they also wanted to reduce their chemical consumption, so they installed UV systems on all their pools as well VFDs on all the pool pumps," noted Richard Deakin of Hollandia Pools & Gardens.

In the case of the City of London, there is a "redundancy" designed into all of their systems. They have a mandate to have two pumps on every body of water. One pump is in operation on the pool, and the other pump acts as a backup. Both pumps are plumbed and ready to go, and they switch on and off between pumps every month. As a result, Hollandia installed one VFD on every two pumps. As an example, one of the local community pools has two bodies of water: a lap pool and a wading pool for children. Each body of water has two pumps—one operational and one in reserve—and they switch the pump being used on a monthly basis. "These municipal pools have really high bather loads and cannot afford to be down at any point," Deakin said.

Deakin explained that a typical pool in the City of London is a Class A pool which requires that the water turn over six times per day or once every four hours. The city does require that the pool operate 24/7. The pumps are pulling and pushing water through the filtration system and as the filters get dirtier, the pumps need to speed up or slow down to meet the mandated city code flow rates. By putting a flow meter on the VFDs with the appropriate set points input into the flow meter, the VFD is then controlled by the flow meter readings.

Deakin understands the power of the cost calculator. He regularly shows prospective customers the results of previous customers. The City of London, for example, has recognized an overall cost savings of 30 to 60 percent on energy consumption.


For the past several years, we've seen everyone push for energy-saving products, and the swimming pool industry is no different. Remember when you're looking for money to put into that new program at your facility and not sure where to get it—start at the heart of your aquatics facility pool, the equipment room. Whether it's an old pump or motor that needs to be replaced, or the many lights you find in a pool, spa or water feature, there are savings to be obtained—savings would continue annually because these new energy-saving products will last much longer than standard products. Just ask yourself a popular question when looking into changing to energy-efficient products, "What's the cost of doing nothing?" Think of that answer while counting up the savings in your head, and using these cost calculators to assist with the tremendous savings potential that is out there for your aquatics facility or commercial body of water.



Mike Fowler is the commercial marketing and sales manager for Pentair Commercial Aquatics in Sanford, N.C. He has been with Pentair since 1992, starting his career in the technical services department at Purex Pool Products. Fowler has held many managerial roles within the company, including marketing, customer management, accounting and products. For more information, visit