Obviously HVACR contractors can’t help their clients solve all of these issues, but they can offer tremendous assistance as supermarkets and grocery stores seek to improve their energy-efficiency and move into a future of low-global warming potential (GWP) refrigerants.

Paul Anderson, senior director of engineering, Target Corp., discussed Target’s ongoing transition to sustainable refrigerants and systems, which includes modeling CO2 cascade, CO2 transcritical,  hydrofluroolefin (HFO) blends, and hydrocarbon (HC) or R-290 systems.

“What I’ve learned from all the research and testing we’ve done over the last few years is that there’s no silver bullet,” Anderson said. “But there are a number of solutions today that, if applied correctly, can help you achieve your desired outcome.”

He added that Target uses a total cost of ownership approach to evaluate the viability of new technologies, including refrigeration systems and refrigerants. The criteria considered include the reliability of the technology; the capital investment, which includes the original price of the equipment and the installation cost; the energy use associated with the new technology; and the repair and maintenance expenses associated with it.

Harrison Horning, director of equipment purchasing, maintenance and energy, Hannaford Retail Business Services, shared insights from his store’s experience with retrofitting a traditional hydrofluorocarbon (HFC) rack system to a transcritical CO2 system.

He noted that replacing old racks in an operating store is inherently complicated and requires a carefully planned construction sequence, contingency planning, and overnight construction to ensure that everything in the store is up and running by 7 a.m. each day.

“Anytime you go into a store and replace an existing rack system, it’s a big deal,” Horning said, “but with CO2 there are additional challenges.”

These include the need to keep a supply of R-744 on hand and use equipment and piping specified for use with R-744; considering both low-temperature and medium-temperature loads for initial startup; providing leak detection and alarms in walk-ins and the compressor room; and an increased need for manufacturer support for training, parts, and programming.”

When it comes to using low-charge ammonia systems, Michael Lehtinen, director of marketing, Heatcraft Worldwide Refrigeration, said a recent project at a PigglyWggly store stressed the importance of hands-on training for the contractor. He pointed out that many supermarkets have existing relationships with contractors and would like to maintain those relationships but realize their contractors may have limited experience with ammonia systems or other natural refrigerants.

“The success of natural refrigerant systems really lies in teaching everyone who has their hands on it — from the store level, to the contractor, to the system operator — to make sure everyone is on the same page,” Lehtinen said.

In the case of an ammonia system, Lehtinen suggested contractor training should include ammonia rack charging and startup; ammonia pump down and charge recovery; replacement of the coalescing filter element in the oil separator; oil charging and system oil balancing and monitoring; and replacement of the oil regulator float, check valves, and liquid level sensors.

Thomas Mathews, president, Baseline ES, talked about the Internet of Things (IoT) for facilities maintenance. The IoT can be a boon by allowing for the capture of high-granularity data about supermarket equipment and systems via the internet. That data can then be used to more efficiently and/or economically operate the equipment and systems.

“K.I.S.S. — Keep it Simple, Stupid — is dead,” Mathews said. “The complexity of newer technologies and refrigeration systems is quite high, and the punishment you get for not operating these systems at their desired control configurations is substantial. Keep it simple is over because that led to energy usage that was higher than it needed to be and confined us to simple systems that used refrigerants that were forgiving. That’s not where we are anymore, and the IoT is a way to keep increasingly complex systems operating properly.”

In a session on HFO options for supermarkets, Ron Vogl, global technical service manager, Honeywell, said HFO blends and single-component HFOs allow for a great deal of flexibility in new store design, making them an increasingly popular choice for retailers.

Vogl noted that HFOs can be used in conventional central direct expansion (DX), distributed DX, cascade, secondary, and stand-alone systems.  

“In each one of these applications that you’re currently using, there is an HFO product that you can slip in now or in the very near future,” he said.

And while there are good reasons retailers are choosing HFOs for new stores, there is a huge installed base of HFC systems that would benefit from a retrofit to HFOs.

According to Vogl, retrofitting to HFO blends provides a chain with a quick way to reduce its carbon footprint, a reasonable payback, and a prolonged life for aging equipment.

“Properly executed retrofits provide improved energy efficiency both from better thermodynamics and recommissioning,” he said.

Bruce Campbell, national accounts manager, supermarkets, United Refrigeration Inc., talked about building a technician workforce in a climate of shifting demographics.

“There isn’t a week that goes by that a contractor doesn’t talk to me about the shortage of good, qualified refrigeration service technicians,” Campbell said.

But in the face of the industry’s most pervasive problem  — the challenge of finding, training, and retaining technicians — Campbell closed with five potential solutions for the industry to apply:

• Create internship programs to give candidates the experience of working as a technician;
• Pass on your knowledge and experience. Teach. Mentor a candidate who shows aptitude;
• Encourage your state to develop a professional licensing program for HVACR technicians;
• Develop eLearning courses in refrigeration, and make them available to vocational-technical schools and other educational programs; and
• Partner with community colleges — promote the development of more associate degree programs in HVACR technology.   

The 2018 FMI Energy & Store Development Conference will take place Sept. 23-26, 2018, in Atlanta. For more information, visit www.fmienergysd.com

Publication date: 12/4/2017

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