By Peter Gaydon
As the new normal is being shaped by COVID-19, facility managers, engineers, and executives have an opportunity to re-examine building priorities to create operational efficiencies, specifically energy and cost savings. In fact, in 2020 there may be 162.9 terawatt-hours of energy savings and subsequent lifetime cost savings of $14.6 billion hiding in new projects and retrofits throughout U.S. commercial buildings, water, and power infrastructure.
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According to the EPA’s greenhouse gas equivalency calculator, that greenhouse savings would represent carbon sequestered by more than 1.9 billion tree seedlings grown for 10 years. It’s equivalent to the CO2 emissions from more than 12.9 billion gallons of gas consumed and a year’s worth of electricity for more than 13 million homes. That potential lives in the pump systems that heat and cool buildings, generate power, run industrial plants, and irrigate farms. By re-evaluating current pump systems and implementing more energy-efficient solutions, companies can generate long-term savings without sacrificing reliability.
Energy and cost savings will vary depending on a variety of factors for different settings, but properly selecting pumps and ensuring they have a Hydraulic Institute (HI) Energy Rating Label will increase the savings. For example, utilizing water pumps with an HI Energy Rating of 50, in a typical mid-sized commercial building using 20 pumps with an average 15-hp rating, you could expect to see a savings of 411,000 kWh per year, or $37,000 per year. In an industrial plant using 40 pumps with an average 15-hp rating, you could see a savings of over 1.3 million kWh per year, equating to an approximate savings of $117,000 per year.
These savings can be even more significant when calculated alongside other pump systems within the same building or application, leading to significant cost and energy savings to help meet business and sustainability goals. Determining the right pump to save energy in a given application can be broken down into three general steps.
Step 1: Analyze The Requirements Of A System – Not Just A Single Pump
It is important to understand that all pumps are selected to meet system requirements—never the other way around. Once the application is determined, engineers can assess criteria, which varies greatly between different uses. For example, a hydraulic heating pump intended to circulate water will require different flow rates and attributes than water distribution pumps in residences or businesses.
The energy consumption required for any system depends on the total system flow rate, the pressure (head) and how often the pump(s) are operating.
By reviewing the entire system and not just the individual pump, engineers and specifiers lay the foundation to select the right pump or system for the application and the proper control methodologies to manage the flow of energy and ensure reliability. The most important question to ask is how much flow/pressure does the system need and how often does it need it?
Step 2: Identify Optimization Opportunities
To be accurate in the determination of energy consumption, the next step is to evaluate opportunities for efficiency gains in system flow, pressure/head, and pump, motor or drive efficiency, and operating time. In existing systems, the energy requirements can be measured over time as a benchmark to aid in identifying where energy consumption can be optimized.
The time period for this process may need to account for seasonal variations, so an entire year may be needed. In contrast, a batch process for a system’s specific task (e.g. provide 100 gallons per minute (gpm) of water around a reactor to maintain 200 degrees Fahrenheit for one hour), will be a much shorter benchmark because the periodic operation is known and consistent.
In another example, a building may need more heat or cooling when it is occupied during business hours and less when business is closed. Multiple thermostats in that building may require different flows at different times, meaning the needs can vary on certain days and during different times of day. As many buildings and facilities are experiencing occupancy disruption amid social distancing and staggering schedules, smart pumps with sensors to monitor flow requirements and adjust speeds accordingly can dramatically improve efficiency and cost savings.
Step 3: Energy Saving Pump Selection
Pump system energy consumption is dependent on the system flow rate, head, component efficiencies, and operating hours at these conditions. There could be opportunities to reduce the head or flow rate through better control that could reduce the piping systems power requirement and the input power to the pump. Understanding the variances and resulting operating points allows us to calculate potential savings of new pumps and/or system controls. It’s important to select the best control that meets the varying system demand without artificially increasing the head/pressure or flow rate to do so, and to maintain the operation of the pump(s) at or near highest efficiency point to maximum reliability and system efficiency.
This three-step process is a framework for any decision maker to help evaluate their current system, identify opportunities for improved efficiency, and realize energy and cost savings over time to help meet broader operational efficiencies.
To better utilize financial and energy resources, HI’s Energy Rating Label, Pumps System Assessment Professional (PSAP) certification, and educational products, can help evaluate current systems and identify energy efficient pumps or integrated systems that helps facilities collectively be more sustainable.
Specifiers can visit this page to learn more about HI’s Energy Rating Program, suite of resources, and search the energy rating pump database to find energy-conserving solutions for various settings and applications.
Peter Gaydon is Director of Technical Affairs for the Hydraulic Institute (HI). HI’s mission is to advance the pump manufacturing industry by becoming the world’s resource for pumping solutions and advancements in the industry.
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