Making a splash by helping MN pool techs save energy & money
Research Insights share findings from CEE's energy efficiency research, drawing real-world links to help Minnesotans save energy and money, while lowering carbon emissions.
Indoor public pools are a gem in cold climate states like Minnesota, allowing residents to engage in a much-loved summer activity (swimming!) all year long. This is why it’s important to think about energy efficiency and indoor public pools — particularly because they use a ton of energy, more than any other location in a building.
CEE’s research project, Optimized Operation of Indoor Public Pool Facilities, found that energy savings can be achieved with HVAC recommissioning and variable speed pool pumps.
Led by senior mechanical engineer Russ Landry, P.E., the project found that 2,000 buildings in Minnesota with indoor public pools could save about 550,000 MCF (thousand cubic feet) and 28,700 megawatt-hours of energy. The project looked at schools, fitness centers, multifamily, and hospitality buildings. Findings show that indoor pool facilities across our great state can lower their operating expenses and reduce their environmental footprint by implementing a few energy saving measures — a win for the planet, and for cutting costs.
“Even though we saw an interesting variety of equipment types and sizes, we kept seeing the same two themes for energy saving opportunities," explains Landry. "Don’t bring in more outside air than needed and don’t pump the pool water faster than needed."
The project also helped address a few other important factors about energy efficiency and indoor public pools, specific to our region.
For one, there aren’t many resources available for operators with an interest in making their facilities more efficient, including Conservation Improvement Program providers and technicians. To solve this challenge, CEE’s research team analyzed previous field study findings and made feedback-informed updates to two reference guides to assist recommissioning providers and pool operators. The team also developed technical savings calculation recommendations that support energy efficiency.
Here are a few energy and money-saving tips for public pool technicians and operators:
Cut costs by reducing water evaporation with a traditional or liquid pool cover. Liquid pool covers consist of a thin layer of alcohol based liquid that naturally covers the surface of a pool. The resulting layer saves energy by lowering the evaporation of water, a major source of heat loss.
Understand how your building uses energy to prevent energy waste. HVAC recommissioning (examining and evaluating how the systems in a building use energy) is an excellent way to improve indoor air quality and efficiency.
Bring pool pump flow rates down to required levels by choosing a variable speed pump, instead of a single speed pump. A pool’s pump is the secret to how it operates. The pump pulls water from the pool through the skimmer and the main drain, pushes it through the filter and heater, and then returns it back to the pool through the main returns. Single speed pool pumps are often too big for the job, and slowing down the pump is the most efficient way to capture lower energy costs; this is accomplished by bringing the flow rate down to an appropriate level.
For larger pumps with separate motors, variable speed drives are usually the best way to bring the pump speed and flow down to the right level. For smaller pumps with built-in motors, replacing them with variable speed pumps is often a great option.
CEE project page: Optimized Operation of Indoor Public Pool Facilities
Final report: Optimized Operation of Indoor Public Pool Facilities
Recommissioning Guide: Indoor Public Pool Facilities in MN
Operator's Guide: Energy Efficient Indoor Public Pool Operations
For residential pools, Energy Star rated variable speed pumps can be used to reduce pump power, or eliminate it completely when the pool isn’t being used. Or, when a variable speed drive or pump replacement isn’t cost effective, even throttling down valves to get the flow down to appropriate levels can lower energy costs.
To learn more about CEE’s work to optimize operation of indoor public pool facilities, and other CEE projects, check out our project pages and upcoming Field Notes.