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Posts tagged ‘Technician’

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.

Mobilizing the Industry to Address the Technician Shortage

RajanRajendran Rajan Rajendran | V.P., System Innovation Center and Sustainability

Emerson Commercial & Residential Solutions

This blog originally appeared in our recent edition of E360 Outlook. Click here to read the issue in its entirety.

With all the talk about the regulatory challenges facing the commercial refrigeration industry today, it’s sometimes easy to overlook the elephant in the room — namely, its growing shortage of qualified HVACR technicians. While we’ve all been justifiably focused on understanding system design changes to reduce energy consumption and new refrigerants to lower our carbon footprint, no one in our industry has stepped forward to lead the charge on solving the technician shortage in a holistic manner.

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At Emerson’s annual contractor roundtable, the lack of qualified technicians was cited as the number one challenge facing contracting business owners. I would argue that it is perhaps our industry’s most pressing issue.

There is no quick fix to this situation. Finding a solution will take months, if not years, and require the commitment of a dedicated organization to drive this effort forward. Through our E360 platform, Emerson is committing to lead this important initiative.

At our E360 Forum in Tucson, Ariz., we took our first steps toward defining the framework of this effort. The event assembled industry stakeholders and vocational school educators for a half-day, E360 Industry Challenge session to examine the current state of the HVACR technician profession. Areas of focus included:

  • Awareness — Do we understand what’s at stake and agree on the problem?
  • Recruitment — How can we attract individuals with aptitude?
  • Training — How can these individuals receive training, and what should those programs look like?
  • Certification — Which types of certification should be made available?
  • Retention — How can we keep individuals engaged throughout their careers?

In 2017, E360 will host a larger Forum focused solely on addressing the technician shortage. This multi-day event will feature an interdisciplinary team dedicated to understanding the problem, defining a working road map for meeting the challenge, and assigning specific actions to solve it.

In addition to industry stakeholders, we will seek insights from previously untapped resources. We will also seek the expertise of educators who have experience in developing curriculum and recruiting candidates. Our technical colleges, vocational schools and trade associations will all play key roles in shaping this piece of the puzzle. We may also benefit from government representatives and/or agencies who may be able to affect policy changes that can further our cause.

Certainly, the current regulatory climate is a dynamic situation that will continue to impact us for years to come, and our E360 platform will remain dedicated to helping you navigate this changing landscape. But without qualified technicians to service the next generation of refrigeration equipment, our industry will have an even bigger challenge.

If you want to contribute to this effort or have ideas that may help, please reach out to us at E360. Stay tuned for updates on this topic.

The Top 10 States to Work in HVACR

One of the key challenges facing the HVACR industry is a shortage of qualified technicians. We thought it would be interesting to elevate this issue and create a list of top 10 states for HVACR, based on our conversations with contractors and HVACR students and instructors about what motivates young people to pursue careers in this industry.

Do you live in one of the top states for HVACR jobs, salaries, training or service calls?

Emerson’s Top States to Work in HVACR

  1. Top Places to Work in HVACRCalifornia
  2. Ohio
  3. Florida
  4. Texas
  5. Illinois
  6. New York
  7. Pennsylvania
  8. New Jersey
  9. North Carolina
  10. Georgia

We arrived at our ranking by drawing on HVACR salary and employment data from the U.S. Department of Labor; trade school locations recognized by the Partnership for Air-Conditioning, Heating, Refrigeration Accreditation; heating and cooling degree days calculated at DegreeDays.net; residential home values from the U.S. Census, and certified contractors by state from North American Technician Excellence (NATE). We also looked at wholesaler locations, plus commercial service volumes from our ProAct™ Service Center.

We gave a few contractors an early look at our list, including frequent Climate Conversations commenter Mitch Byrne of  Northeast Cooling LLC in Illinois. He said: Commercial refrigeration service is in high demand due to all the businesses related to food service and the restaurants in the Chicago area. We may start off the day working in a max security prison and then end up working on a cruise ship docked at Navy Pier! You never know what the day will bring when working the trade in Illinois and that’s what keeps it interesting!

For more information and analysis on the Top 10 States to Work in HVACR, see our summary and press release.

Do you agree with our list? Want to make the case for another state? Be sure to share your comments here.

Cathy Billing
Marketing Communications Manager
Emerson Climate Technologies

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