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Careful Compressor Selection Improves Refrigeration System Efficiencies

In a regulatory environment where phase-down proposals for refrigerants containing HFCs are giving rise to a new class of refrigerant alternatives, retailers are faced with making decisions about how to design refrigeration systems. Our recent Making Sense webinar, entitled “Best Practices for Evaluating Compressor System Performance,” took a closer look at this issue to help retailers balance sustainability concerns within the contexts of evaluating operating costs, maintenance requirements and readiness of available technology.

From distributed DX rack systems that reduce refrigerant charge to cascading and transcritical booster CO2-based systems, today’s refrigeration systems are become increasingly complex in response to regulatory and consumer demands. Not only do these more complex systems reduce refrigerant charge, they also promise improved energy efficiencies and lower GWP potential. Choosing a compressor that meets these demanding requirements is a critical aspect of refrigeration system design.

Through Emerson Climate’s software-guided selection tools, we’re helping retailers make this important decision. When selecting a compressor that meets your application’s requirements, you must carefully evaluate factors that impact compressor performance:

  • Difference between mid-point and dew point
  • Compressor and evaporator capacity
  • Mechanical sub-cooling and vapor injection

Once retailers have a good idea of fundamental design conditions — from refrigerant choice and mid-point selection to minimum condensing temperature and liquid sub-cooling preferences — they can use our product selection software to recommend the best available compressor option.

As we explained in the webinar, we suggest the following best practices when selecting a compressor for your next refrigeration system:

  • Use mid-point, not dew point, as the basis of the decision, because that’s essentially what the refrigeration system is seeing.
  • To avoid oversizing your system, let evaporator capacity (rather than compressor capacity) inform the decision process. This provides a better reflection of how the system would operate.

At the end of the day, the primary goal retailers should keep in mind is to select a compressor capable of meeting the load at the highest ambient temperature while providing the best annual energy efficiency. To learn more about how to select the right compressor for your application, please visit our Making Sense website and listen to the archived webinar on demand.

Mike Saunders
Director, End User Technical Sales and Support
Emerson Climate Technologies

SNAP, CAP and all That: Feedback From the Recent EPA Meeting on HFCs

During the past several months, the Significant New Alternatives Policy (SNAP) program hosted a series of sector-specific workshops and a broad stakeholder meeting. In February, I participated in the EPA’s broad stakeholder meeting on possible future actions and direction concerning hydrofluorocarbons (HFCs) under the SNAP program and the Climate Action Plan (CAP).

The purpose of the February 2014 meeting was to promote a dialogue between stakeholders and the EPA on possible next steps and effective approaches to meet the president’s goals under CAP. At the meeting, the EPA announced plans for two separate SNAP rule-making proposals this year:

Expanding the list of low-GWP refrigerants for air conditioning and refrigeration applications — under consideration are ethane, iso-butane, propane, R-441A (HC blend) and HFC-32. All of these refrigerants (except HFC-32) have a GWP of less than 10. Since these refrigerants are also flammable, the EPA is planning to adopt safety standards and propose specific uses for each refrigerant. The EPA expects to move on this in spring 2014.

Changing the approval status of certain high-GWP HFCs in specific applications — the EPA is not expected to issue any across-the-board GWP limits, but instead will consider the end use and target-specific applications where viable options already exist and are being used. For instance, a high-GWP refrigerant in one application may be considered in the low- to mid-range for another. In addition, servicing existing equipment will not be impacted to help prevent stranding capital.

The five proposed specific application and HFC status changes include:

  • Vending machines and stand-alone, reach-in bottle coolers — changing the status (banning the use) of R-134a and blends with a higher GWP
  • Multiplex supermarket refrigeration — banning the use of R-404A, R-507A, and blends with a higher GWP. Retaining R-407A/C/F and R-134a or any approved refrigerant with a GWP lower than R-404A and R-507.
  • Motor vehicle air conditioning — banning the use of R-134a
  • Non-medical and non-technical aerosols — banning the use of R-134a, HFC-227ea and HFC-125. Retaining HFC-152a.
  • Various foam blowing — banning the use of R-134a and higher-GWP refrigerants

The EPA expects to move on this in summer 2014.

We believe these proposals are a logical approach to CAP and welcome additional clarity to HFC action in the industry. However, these measures will not be accomplished without significant investments by our industry in equipment and training, and these investments need to be considered in conjunction with the recent U.S. Department of Energy’s proposed improved energy efficiency standards for commercial refrigeration equipment.

Stay tuned for further details including effective dates as the actual proposals are targeted for release this spring and summer. Emerson will continue to be involved in the process and provide feedback when appropriate to the EPA. We are open to arranging discussions around this topic and look forward to your thoughts on these proposals.

Rajan Rajendran, Ph.D.
Vice President, Engineering Services and Sustainability
Emerson Climate Technologies

Best Practices for Evaluating Compressor System Performance — Making Sense Webinar

To help select the proper refrigeration equipment in specific applications, many commercial retailers today are closely monitoring their compressor systems for valuable performance data. One way this is possible is through the use of software that calculates performance in a variety of scenarios. Whether through conducting annual energy analyses or evaluating efficiencies based on geographic locations, retailers are using the power of software tools to improve visibility across their operations.

In our next installment of the Making Sense webinar series, we’ll take a closer look at this subject and discuss the best practices for evaluating compressor system performance. We’ll explore the following key concepts:

  • Comparison of compressor and evaporator capacities
  • Mid-point and dew point compressor selections
  • Difference between Energy Efficiency Ratio (EER) and Annual Energy Efficiency Ratio (AEER)

And, you’ll learn how to use software to improve a variety of operations, planning and analysis activities, including:

  • Equipment planning and selection
  • Calculate annual compressor performance
  • Conduct energy analyses
  • Evaluate compressor performance in specific geographic locations

You’ll find there are many ways that compressor system performance data can help you improve operational visibility.

Our second webinar in the “Operational Visibility” category will be presented by Emerson Climate’s own Mike Saunders and Autumn Nicholson. Mike is the director of end user technical sales and support and has more than 18 years of experience in refrigeration product development. As a senior sales engineer, Autumn’s an expert on compressor and refrigeration system energy and Total Equivalent Warming Impact (TEWI) analysis, with a focus on refrigeration alternatives and system architecture.

Join us on March 11 at 2 p.m. EDT to learn the best practices for evaluating compressor system performance. Register now by visiting our website at While you’re there, be sure to check out the archives of other Making Sense webinars — it’s how we’re helping the refrigeration industry MAKE SENSE of the issues that matter most.

Craig Raney
Director of Marketing, Refrigeration
Emerson Climate Technologies

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