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Optimize Supermarket Energy Efficiency and Performance With VFD Retrofits

Joe Summers | Senior Product Manager – Scrolls & Drives
Emerson’s Commercial & Residential Solutions Business

The use of fixed-speed (or fixed-capacity) refrigeration systems and HVAC rooftop units (RTUs) is a common strategy in the U.S. food retail sector. If you went into the machine rooms of most grocery stores, you likely would find centralized, direct expansion (DX) refrigeration systems with parallel racks of fixed-speed compressors. On the rooftops, you would find RTUs with air-handler blowers running continuously at full speeds. Varying the capacity of these critical units relies on mechanical throttling techniques that consume energy, cause excess equipment wear, but never quite achieve the desired load matching. In a new white paper, Emerson explore how operators can retrofit these systems with variable frequency drives (VFDs) to deliver significant energy efficiency and performance improvements.

For the most part, the potential uses for VFDs in the food retail sector have been largely unexplored. Simply put, VFD retrofits allow operators to convert existing fixed-speed equipment — such as compressors, fans or pumps — to enable variable-capacity modulation. Benefits include:

  • Reduced energy consumption and electricity costs
  • Improved load matching, temperature precision and performance
  • Extended equipment reliability lifespan

VFDs in refrigeration systems

The inability to match the refrigeration capacity to fluctuating evaporator load demands is a known limitation of parallel rack systems with fixed-speed compressors. Systems are designed and specified to accommodate peak-load conditions and provide reliable cooling during the hottest days of a year — i.e., they’re essentially over-sized for lower load conditions and cooler periods.

Widely varying load requirements, ever-changing ambient conditions and variations in defrost cycles can create undesirable fluctuations in case temperatures. Compressors are constantly switching off and on to try and adapt to these changing demands, which can accelerate wear on system components, increase the potential for food quality issues, and consume excess electricity.

VFDs give operators and service technicians an effective method for alleviating fixed-speed compressor motor challenges and achieving the benefits of variable-capacity modulation. By retrofitting a VFD to the lead compressor in every parallel compressor rack, each lead compressor can then modulate the capacity of the entire rack. This enables fixed-speed compressors to handle the base load, while leveraging the VFD-equipped lead compressor to manage fluctuations in demand. Compared to a traditional fixed-speed approach, this results in:

  • Reduced cycling on/off strain and an extended life of the lead compressor
  • Smoother and almost constant system suction pressure
  • More consistent evaporator (case) temperatures and humidity conditions

Validating VFD ROI in HVAC case study

In HVAC RTUs, air-handler blower capacity is also designed to handle the peak cooling conditions of the installation’s summer season. But as building loads fluctuate widely throughout the year, HVAC systems often operate at only a fraction of their design capacity. Thus, air-handler blower fans run continuously at full, fixed speeds, regardless of load requirements. Technicians often use a mechanical throttling technique to help reduce airflow, but this results in increased energy consumption and a reduction in the equipment’s lifespan.

Retrofitting a VFD onto an existing fan motor allows it to modulate capacity based on varying load requirements — full speed during peak-load periods and slower speeds when less load is required. In this HVAC RTU application, variable-capacity modulation delivers a fast return on investment (ROI) via a non-linear, speed-to-power ratio. By slowing down a blower motor fan speed by 25 percent of its normal operating rate, it’s estimated that facility operators can reduce energy consumption by 50–60 percent.

Emerson validated this principle recently by installing Copeland™ VFDs on a food retailer’s existing rooftop HVAC air-handler blower motors in 78 of their stores. Results included:

  • Reduced energy consumption by 52 percent
  • Saved more than $800,000 in electricity costs
  • Equivalent to adding $10M in sales at an 8 percent margin

Retrofit with Copeland VFDs

Emerson is committed to helping food retailers and technicians to simplify the retrofit process in HVACR applications and improve equipment reliability, performance and efficiency. Copeland VFDs, EVM/EVH Series are designed to reduce the costs and complexities of VFD implementation:

  • The Copeland EVM Series is ideal for chillers, medical refrigeration, display cases, walk-ins and reach-ins.
  • The Copeland EVH Series is designed for large, centralized racks (including CO2), HVAC applications, advanced chillers and industrial refrigeration applications.

Learn more about applying our VFD solutions to your HVACR operations by visiting our webpage.

Discover the Case for Natural Refrigerants at ATMOsphere America

Andre Patenaude | Director – Solutions Strategy

Emerson’s Commercial and Residential Solution’s Business

For decades, natural refrigerants have been used worldwide as environmentally friendly alternatives to high global warming potential (GWP) refrigerants or ozone-depleting substances (ODS). As the U.S. commercial refrigeration industry faces an imminent phasedown of hydrofluorocarbon (HFC) refrigerants, the stage is set for natural refrigerants like CO2 and R-290 to play much larger roles. Emerson is pleased to announce our participation in the ATMOsphere America Summit 2022 on June 7–8, where our experts will present new data that supports the expanding business case for natural refrigerants.

With the phasedown of high-GWP HFC refrigerants underway, commercial and industrial refrigeration stakeholders are actively planning for the next generation of refrigerant technologies. As corporate-led environmental initiatives are pledging to use more sustainable equipment, CO2 and R-290 are widely considered to be among the leading natural refrigerant candidates to anchor future refrigeration strategies.

Today’s market is evolving rapidly — and Emerson is at the leading edge of technological advancements supporting the use of these proven natural alternatives. We’ve made significant investments in research and development (R&D) projects and lab testing capabilities designed to:

  • Promote the use of low-GWP refrigerant technologies
  • Support original equipment manufacturers (OEMs) in their design cycles
  • Help end-users to make successful refrigerant transitions

Join us at the ATMOsphere America Summit 2022

As a gold sponsor of the upcoming ATMOsphere America Summit 2022, Emerson is looking forward to presenting data from our recent R&D efforts which explore the expanding role of natural refrigerants. This in-person-only event will take place on June 7–8 in Washington, D.C., at the Hilton Alexandria Mark Center. Join peers, industry experts, policymakers, end-users, and contractors to explore the latest natural refrigerant trends and technologies.

Emerson’s participation will feature informative sessions and panel discussions highlighting our latest natural refrigerant research:

  • Making the case for sustainable CO2 in supermarket refrigeration (June 7 at 2 p.m. EDT) — which will be presented by me and Zero Zone
  • Exploring the climate zone impacts on CO2 system selection (June 8 at 10 a.m. EDT) — which will be presented by me
  • Panel discussion sharing the latest policy and market trends impacting natural refrigerants (June 7 at 11 a.m. EDT) — which will be presented by me

If your company is interested in exploring a future based on natural refrigerants, register now and make plans to attend this in-person event. Be sure to stop by any of the Emerson sessions and ask how we can help you on your journey to more sustainable refrigeration.

 

 

 

Refrigeration Retrofit: Installing Copeland™ Variable Frequency Drives, EVM Series

Eric Grilliot | Application Engineer

Emerson’s Commercial and Residential Solution’s Business

Many supermarket and facility operators are looking for opportunities to retrofit their existing HVACR equipment to improve energy efficiency, reliability and performance. With the recent launch of Copeland™ variable frequency drives (VFDs), EVM Series, contractors have new opportunities to help their customers achieve these goals. In fact, our EVM Series drives can be installed on existing fixed-speed HVACR motors without having to swap out or replace equipment, resulting in faster and more affordable retrofits.

I recently produced an instructional video to cover EVM Series installation best practices within a refrigeration rack and demonstrated their user-friendly startup wizard.

Unboxing your EVM drive

Before you begin the installation process, it’s important to make sure that you have the correct model and verify that it did not incur any damage during shipping.

  1. Remove the drive from the box and verify that the model number on the nameplate matches what’s on the shipping box label.
  2. Inspect the drive to ensure there are no cracks and/or visible damage.
  3. Review the quick-start guide, and follow the quick-start guide and installation manual during installation.

Installation and mounting considerations

Choosing an installation location is key to protecting the drive and enabling easy access to it and the compressors in the rack.

  1. Identify the fixed-speed lead compressor that will be retrofitted.
  2. Select a location to install the drive where it will not be exposed to moisture (from weather, refrigeration chiller lines or potential leaks) or excess vibration (from placement within the rack).
  3. Choose a location that won’t restrict access to compressors in the rack or make it difficult to interface with the drive itself (e.g., too high). An ideal location for many applications is within an electrical panel mounted on a din rail for ease of access.

Wiring and connections

EVM Series drives are designed with easily accessible input/output (I/O) terminals and provide a quick reference of their locations on the inside cover panel of each drive. Making connections requires only two flathead screwdrivers: one for the controller wire and one for incoming/outgoing compressor wire connections. Before making electrical connections, be sure to follow proper lockout and tagout procedures on high- and low-voltage wires. Double-check with a voltage meter to make sure there’s no chance of receiving an electrical shock.

  1. Remove the drive’s cover panel and review I/O terminal locations (see installation guide for more information).
  2. Connect the incoming power source to L1, L2 and L3 on the underside of the drive.
  3. Connect U, V and W (outgoing power source) to the compressor.
  4. Be sure to connect the incoming power ground as well as the motor to the drive’s ground terminals.
  5. Connect the control wire to the refrigeration control device (e.g., Lumity™ E3 supervisory control) to enable variable frequency control. Note: the control interface also supports Modbus connection. See Application Engineering Bulletin AE8-1456 for more information.

Configure startup parameters

Once your drive is installed and powered up, the built-in startup wizard should make it easy to set the parameters and configure it with your specific compressor. Consult pages 29–30 of your installation manual and review step 4 for full startup wizard instructions. Check the compressor’s motor nameplate for much of the information needed to complete startup parameters. Note: this information is also available on the Emerson Online Product Information (OPI) webpage and the Copeland Mobile app. Recommended steps include:

  1. Power up the drive to bring up the onboard display and access the startup wizard.
  2. Press the down arrow and navigate to “S” for startup wizard. Press OK to initiate.
  3. Accept or change the default password (P13.1.7).
  4. Select the minimum frequency setting (option P1.1). Note: every compressor application will be slightly different. Check with your Emerson sales representative, application engineer or applicable AE bulletin for more information.
  5. Select the maximum frequency (option P1.2).
  6. Select the motor nominal current (option P1.6).
  7. Select the motor nominal speed (option P1.7).
  8. Choose a power factor (option P1.8); the default setting is .85.
  9. Select the motor nominal voltage (option P1.9).
  10. Select the motor nominal frequency (option P1.10); 60 Hz for U.S. installations.
  11. Set the acceleration time (P1.3); the default setting is 20 seconds
  12. Set the deceleration time (P1.4); the default setting is 20 seconds.
  13. Select the remote-control place (P1.13); fieldbus =
  14. Select the remote reference (P1.14); fieldbus = 7.

As I demonstrated in my instructional video, this entire startup configuration can typically be completed in a matter of minutes. To learn more about the Copeland EVM Series drives or the many benefits of VFD retrofits in HVACR equipment, please visit our website.

 

 

Warm-weather CO2 Strategy Helps Retailer to Hit Sustainability Target

Andre Patenaude | Director – Solutions Strategy

Emerson’s Commercial and Residential Solution’s Business

The transition from hydrofluorocarbon (HFC) refrigerants to lower-global warming potential (GWP) alternatives has become a common denominator in many food retailers’ sustainability strategies. Whether your company is in the early phases of its sustainability journey or has already made significant progress in the race to Net Zero, you’ve likely evaluated the potential of CO2-based refrigeration. Among the many misperceptions about CO2 transcritical booster systems is that they are not well-suited for installations in warmer climates. Emerson recently partnered with Zero Zone to help a leading food retailer prove the business case for warm-weather CO2 refrigeration. To view the full article, click here.

Expanding application potential

When calculating the sustainability potential of a refrigeration system, it’s important to look at its total equivalent warming impact (TEWI), including direct carbon emissions from refrigerant leaks and indirect emissions from energy consumption. Although the natural refrigerant CO2 (or R-744) has a GWP of 1, many supermarket owners and operators have questions about the efficiency of CO2 transcritical booster systems, especially in warmer climates.

CO2 transcritical booster refrigeration systems have been installed in Europe for decades and are expanding rapidly around the globe. Today, nearly 1,000 CO2 transcritical booster systems are installed in the U.S., with adoption projected to increase more than 50% by 2025. System designers, original equipment manufacturers (OEMs) and component manufacturers (e.g., Emerson) have made tremendous strides in developing smart CO2 transcritical booster system strategies that:

  • Improve energy efficiencies in warmer climates
  • Optimize system performance and reliability
  • Lower the total cost of ownership (TCO)
  • Simplify system start-up, operation, high-pressure management and maintenance

Retailers who are now looking at CO2 for the first time will benefit from years of installations and supermarket trials that have significantly improved upon CO2 transcritical booster equipment technologies.

Proving the business case

In a recent collaboration, Emerson partnered with refrigeration OEM Zero Zone to help them design and install a CO2 transcritical booster system for a new supermarket in Joplin, Mo. Due to the location’s warm climate, the design team recommended an emerging high-ambient mitigation strategy designed to maximize the efficiency of CO2 during the summer season. The goals of the project were to help the retailer to meet their sustainability targets while maintaining the highest standards for food quality and safety.

The climate in Joplin averages more than 200 annual hours above R-744’s critical point of 87.8 °F. During these warmer temperatures, a CO2 transcritical booster system would typically enter transcritical mode and consume electricity at a higher rate, but the Emerson and Zero Zone system has been designed to operate efficiently across even these high-temperature ranges. With recent advances in system technologies, stakeholders can choose from multiple CO2 strategies designed to mitigate high-ambient temperatures, minimize transcritical operation, and maximize energy efficiencies.

For the Joplin installation, Zero Zone and Emerson opted to utilize an adiabatic gas cooling strategy on the system’s outdoor condenser/gas cooler. When summer heat builds and R-744 pressures begin to rise within the gas cooler, water is misted onto adiabatic cooling pads — effectively keeping R-744 below its critical point during warm stretches and dramatically improving system efficiency. Today, this installation is operating as designed for Zero Zone’s food retail customer, delivering year-round efficiencies and refrigeration reliability.

The system features a full suite of integrated Emerson CO2 technologies — from low- (LT) and medium temperature (MT) compressors to CO2 refrigeration rack controls case controls and high-pressure controls — that are helping Zero Zone to prove the business case for warm-climate CO2 systems. Not only have these technological advances greatly expanded the potential of CO2 applications in diverse climates, but they’re accelerating CO2 adoption for a new generation of end-users and service technicians.

For more information about the high-ambient CO2 mitigation strategy used in this installation, you can read our case study. To learn about Emerson’s commitment to developing integrated CO2 technologies, please visit our CO2 information hub.

Regulatory Round-up: AIM Act, CARB, A3 and A2L Charge Limit Increases

Jennifer Butsch | Regulatory Affairs Director

Emerson’s Commercial & Residential Solutions Business

If you’re like many stakeholders in the commercial refrigeration industry, you know how important it is to keep track of the dynamic regulatory climate. From making refrigerant decisions and selecting next-generation equipment to plan for compliance and meeting sustainability goals, many companies are basing some of their most important decisions on these developments. I recently provided an article to HVACR Business that reviewed several key regulatory updates taking place this year. If you’re hoping to bring the sometimes-confusing regulatory picture into clearer focus, hopefully this will help. You can also view our formatted article here.

AIM Act establishes federal HFC legislation

Signed into law in late 2020, the American Innovation & Manufacturing Act (AIM Act) gave the Environmental Protection Agency’s (EPA) authority to regulate hydrofluorocarbon (HFC) refrigerants in three primary ways:

  1. Phasing down HFC refrigerant supplies by reducing their production and consumption over a 15-year period. Supply-side restrictions began on Jan. 1, 2022, requiring a 10% reduction in HFC production and consumption through 2023. An additional 30% reduction will take effect between 2024 and 2028 with 70% and 80% reductions needed by 2029 and 2034, respectively. These phasedowns are expected to drive up HFC prices significantly as supplies decrease.
  2. Establishing sector-based approvals and HFC restrictions to support the industry-wide transition to lower-global warming potential (GWP) refrigerant technologies. Use restrictions will enable specific sectors to transition more quickly while providing additional flexibility for those who may need more time. The EPA can approve new lower-GWP alternatives per sector-based rulemakings, which are expected to begin in 2022.
  3. Regulating HFC management by establishing and enforcing standards in servicing and repair best practices, such as: lowering leak rate thresholds and requiring proper recovery of “used” HFCs for purification and resale (aka reclaim). Previously, the EPA had created Section 608 to govern these best practices; we expect their revised HFC management rulemaking could be built off the Section 608 framework.

CARB rulemaking takes effect

After several years of collaboration with state and HVACR industry stakeholders, the California Air Resources Board’s (CARB) proposed rulemaking became final in late 2021 and went into effect on Jan. 1, 2022. The final rule establishes HFC phasedown requirements for new and existing facilities, including a company-wide provision for food retailers operating with a fleet of existing stores within California.

  • New facilities — Installation of new refrigeration systems containing more than 50 pounds of refrigerant are required to use refrigerants with less than 150 GWP.
  • Existing facilities — Refrigeration equipment containing more than 50lbs of refrigerant in existing facilities are subject to company-wide, fleet GWP reduction targets by 2030 compared to their 2019 baselines — with two potential paths to compliance: 1) Weighted-average GWP (WAGWP) reduction <1,400 GWP by 2030, where WAGWP is the sum of the total refrigerant charge of every system greater than 50 pounds in every store in California; 2) Greenhouse gas emissions potential (GHGp) reduction by 55%, where GHGp is the sum of the total refrigerant charge of every system greater than 50 pounds in every store in California multiplied by the GWP values of the refrigerant types in use.

Regarding new stationary air conditioning (AC) equipment, refrigerants with a GWP greater than or equal to 750 will be prohibited, starting in 2025.

Evolving safety standards for flammable (A3) and mildly flammable A2L refrigerants

Governing bodies that regulate the safe use of refrigerants in the U.S. have long been evaluating the prospect of increasing charge limits in the flammable A3 (propane, aka R-290) and mildly flammable A2L refrigerants. In 2021, the Underwriters Laboratories (UL) approved the second edition of its UL 60335-2-89 standard, which included higher charge limits that would expand the potential uses of R-290 and A2Ls in commercial refrigeration.

R-290 charge limit increases — R-290 has a long-held maximum charge limit of 150g and has primarily been used in smaller, self-contained units. The updated UL standard raises the charge limits on these commercial stand-alone displays based on whether they have an open or closed design:

  • 500g maximum charge limit in open appliances (without doors)
  • 300g maximum charge limit in closed appliances (with doors or drawers)

From an application design perspective, higher charge limits will help to increase system capacities while capitalizing on R-290’s high efficiency and low-GWP rating (GWP = 3).

A2L charge limit increases — Per the recently updated UL 60335-2-89 safety standard, new A2L charge limit guidelines have been established for self-contained and remote refrigeration systems. For self-contained equipment, charge limits are determined by equipment design (e.g., open or closed with doors or drawers). Degrees of flammability will vary among different A2L refrigerants, so it’s important to calculate charge limits based on the specific A2L characteristics.

For example, R-454C has a lower flammability limit (LFL) of 0.291 kg/m3, thus:

  • A closed-door case can be charged with up to 2.33 kg (5.1 lbs.) of R-454C.
  • An open case with R-454C can be charged with up to 3.78 kg (8.3 lbs.) of R-454C.
  • In remote or field-erected systems, UL 60335-2-89 supports R-454C charge sizes up to 75.7 kg (166 lbs.) per circuit.

The updated standard requires remote A2L systems to be designed with requisite safety strategies and mitigation measures to keep gas concentrations below flammable thresholds:

  • Leak detection at various points of the refrigeration circuit (e.g., compressor, condensing unit and case)
  • Action plans that immediately mitigate flammability risks

The UL 60335-2-89 second edition update is only the first step in a larger series of regulatory approvals needed to enable higher charges of R-290 and the use of A2Ls in U.S. commercial refrigeration. Additional regulatory and/or policy changes will also need to be approved:

  • EPA Significant New Alternatives Policy (SNAP) approval of specific A2L refrigerants and increased R-290 charge limits
  • ASHRAE 15 safety standard update for refrigeration systems
  • Model code updates in the upcoming code revision cycle, such as: Uniform Mechanical Code (UMC), International Mechanical Code (IMC) and International Fire Code (IFC)
  • State and local building code updates

In the meantime, installing an A2L-based refrigeration system would typically require the approval of local authorities having jurisdiction (AHJ), such as fire marshals and/or building inspectors.

To stay informed of the latest regulatory updates that could impact your operational decision-making, please visit our regulations hub.

 

 

 

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