Make Your Aquatic Facility Lean, Green
By Connie Sue Centrella
“Going green” is an effective and responsible way for businesses to manage their impact on the environment; it is also a way to reap long-term profits and boost the bottom line. These choices can result in a healthier facility for employees and patrons, all while making the facility more competitive.
Management can develop a realistic, well-researched strategy to achieve a sustainable facility by taking the proper steps. This begins with taking a true assessment of how energy is being used. Some of the factors include:
Fuel and water use
Effect on the carbon footprint
All of this can be achieved by making wise decisions based on sound science and conducting an aquatic energy audit.
The audit requires a visual inspection of the aquatic facility’s current environment, including a review of current energy usages and an examination of equipment. These baseline data support future recommendations for renovation.
Additionally, the audit must assess all the operational systems—filtration, heating appliances, ventilation equipment, pumps and motors, chemical-handling systems, lighting (in the facility and in the pool), and controls.
A review of all current energy costs associated with each part of the facility will provide the tools needed to calculate future energy usages and payback time for any recommended changes to the equipment.
Four Steps To Crafting An Energy Audit
1. Assemble an energy-audit team—including the facility manager, pool operators, and maintenance staff—for a range of insights and views; these will provide a more comprehensive approach to the audit.
2. Collect, organize, and analyze the current energy data. Gather gas, electric, and water bills to show the fossil-fuel costs for the heating appliances as well as the water usage to refill the pool(s) due to bather load, backwashing, cleaning filtration equipment, and overall maintenance work.
3. Make a visual on-site inspection of the structural components of the facility, as well as each existing piece of equipment used in the operations.
4. Analyze the findings and write an action report to outline proposed energy conservations and system improvements.
Your audit team needs to inspect all pool mechanicals. Photo courtesy of National Swimming Pool Foundation
This may seem like an overwhelming task; however, assigning a team to manage and conduct an efficient audit and analysis is necessary and does take time, focus, and commitment.
To get started, have your team locate and collect all of the original construction plans and engineering drawings for the facility, along with any subsequent modifications; obtain manufacturers’ specifications on equipment, pool gallons, turnover rates, as well as energy, gas, fuel, water, and chemical-use invoices.
Visual On-Site Inspection
The visual on-site inspection will require the audit team to inspect all facets of the facility.
In an indoor facility, it is important to review the building envelope for structural cracking, as well as window and door air leaks that may increase the heating and cooling costs. These air leaks also can affect the cost of heating the pool(s).
In most instances, pool heating requires use of fossil fuels. Approximately 95 percent of energy (heat) losses come from a combination of evaporation, radiation, and convection, while the remaining 5 percent comes from convection. Convection is energy lost through the pool shell into the cooler ground behind the vessel. It is important to review the heat-recovery system (indoor ventilation systems) as well.
[Tip #1: Converting fossil-fuel heating to a more energy-efficient heat pump or a geothermal heating system, or partnering solar systems with other heating appliances are other alternatives.]
[Tip #2: Research how new heat-recovery units work in conjunction with the pool-heating equipment to maximize heating efficiency.]
Sand-filtration systems require water usage during the backwashing cycle. An inspection of the filters—including the age of the system, sand-replacement intervals, and the time to backwash to a clean system—should be done because the age of the system may influence how much water is used.
The gallons backwashed to the sanitary waste system can be calculated based on flow rates. The environment is impacted by the backwashing of filter dirt and debris (along with pool chemicals) into the lakes and streams, becoming a hazard to the fish downstream.
[Tip #3: Regenerative D.E. filter systems and cartridge filtration use less water and require a smaller footprint.]
The quantity and condition of swimming pool and spa lights, wattages, amps, and volts all influence energy draw. The audit team should analyze the day and night swimming times, and assess the overall cost of the lighting.
This can be calculated using Ohm’s Law: Amps x Volts = Watts and converting to kilowatt-hour usages, which is the way electrical utilities calculate charges. Inspecting all connections and conditions of the lighting is also important.
[Tip #4: Traditional 500-watt halogen lights can be modified to the energy-efficient LED lighting system. LED lighting can also be retrofitted to traditional lighting fixtures. Make sure the new lighting system provides the proper lumens to meet building and health-code requirements.]
Pumps And Motors
The audit team needs to examine the pump’s performance against the original pump curve provided by the manufacturer. The use of a pressure gauge and vacuum gauge can provide the total dynamic head (TDH) necessary to read the pump curve.
Install a vacuum gauge on the suction side of the pump and a pressure gauge on the pressure side of the pump. Multiply the vacuum gauge reading by 1.13 and the pressure gauge reading by 2.31. Add these two calculations and you will have the TDH for this particular pool system. Then compare to the pump curve to ascertain if the pump is performing to optimal gallons per minute.
Over time, impellers can become damaged, which strain the pump, lower flow rates, and increase electrical costs. The audit team should check the current pumps to analyze if any cavitation is occurring.
Also, the flow meters should be inspected for proper sizing. Flow rates need to be correctly recorded and deliver flow and turnover rates that meet state and local health codes.
[Tip #5: Variable and multi-speed pumps and motors are available for commercial use in aquatic facilities. Before installing, confirm that this equipment provides the proper flow rates to meet local and state health codes.]
Chemical toxicity impacts the overall health of an aquatic facility. Many of the sanitizers typically used are hazardous. Creating a sustainable facility requires elimination of toxic chemicals.
The team should conduct a complete overview of chemical storage and handling, including utilization of these chemicals and overall safety.
[Tip #6: The use of electrolytic chlorine generators (salt systems) is gaining momentum, partly because it is non-toxic and offers safe handling. The sizing of these systems includes volume (gallons), average water temperature, presence of cyanuric acid, bather load, direct sunlight/UV exposure, surrounding vegetation and airborne debris, chemical dilution from source water, and filter turnover and circulation patterns.]
More and more aquatic facilities employ the use of controllers and chemical analyzers because they assure greater bather safety. The audit team should inspect the systems, making sure the probes are clean and accurately measure the chemical parameters.
Over time, these systems, if not calibrated, will send false messages to the chemical-feed pumps, rendering water conditions that may be over- or under-sanitized or not balanced correctly
[Tip #7: Chemical controllers and chart recorders can monitor chemical usage and send a message to the facility’s “operation control room,” alerting the pool operator of unsafe water conditions. These analyzers offer not only safety to the facility but oftentimes lower the chemical usages by accurately adding chemicals as needed without human error. It is advisable to perform manual water testing at least once daily to ensure calibration with the analyzer.]
Writing An Action Report
After all the systems have been analyzed, including a thorough review of the usages and costs, a comprehensive action report can be achieved. The report should indicate which areas of the facility need to be modified or renovated to reduce energy consumption. Recommendations for installation of new equipment and payback time should be included. Payback is important to owners. It gives the amount of time it will take to recoup the investment based on energy savings. The audit team should demonstrate how much is currently being spent compared to what is saved.
These compelling data may help encourage facility owners to upgrade to more efficient equipment. The audit team should research current energy-rebate programs offered by various municipalities, and present these rebates in its savings report.
Boosting the bottom line for any aquatic facility in today’s recessionary climate is critical to keeping many doors open for the public. Lowering energy costs and finding greater efficiencies throughout must be the goal for a healthy facility in the long run.
It is valuable to look at the existing facility and examine all costs before making a quick decision to modify. To be successful in assessing a facility, the audit team must do its homework, calculate the energy savings and the life cycle of the systems, assess the annual maintenance costs, and compare the return on the investment.
Connie Sue Centrella is a professor and Program Director for the online Aquatic Engineering Program at Keiser University eCampus. She is a five-time recipient of the Evelyn C. Keiser Teaching Excellence Award “Instructor of Distinction.” Centrella is an industry veteran with over 40 years experience in the pool and spa industry. She is a former pool builder with extensive knowledge in pool construction and equipment installation, as well as manufacturing.
Facility Energy-Audit Form Checklist
√ Original construction and engineering plans
√ List of any modifications or renovations
√ Manufacturer equipment manuals
√ Copies of 12-month invoices on electrical, gas, and water
√ Type of structure, interior surfacing
√ Pool volume, surface area, and special water features
√ Lighting (external fixtures, type and number)
√ Interior lighting (type of fixture and wattage)
√ Air-quality system (ventilation and heat recovery)
√ Electrical sources
√ Filtration/circulation equipment
√ Number of pumps, HP, phase, and rating capacity (gallons per minute)
√ Filter type, sand-replacement intervals
√ Vacuum-gauge and pressure-gauge readings
√ Heating equipment and energy source (BTU output)
√ Water and chemical treatment
√ Chemical analyzers and controllers
Become A Certified Aquatic Energy Auditor
Conducting an audit is the first step to improving energy efficiency. The Online Certified Aquatic Energy Auditor (CAEA) course from the National Swimming Pool Foundation is designed for aquatic professionals to audit and recommend energy-efficiency solutions and improvements. In this course, you will learn:
The basics of a circulation system
Contributions to energy consumption
Performing an energy audit
The steps from performing an audit to recommending and making changes.
This includes an online course and handbook. For more information, visit www.nspf.org/online.