Naturally chilly

Natural refrigerants, improved compressor technology and monitoring systems are among the advancements in refrigeration systems.

By Kim Ann Zimmermann

Like many of the foods that they keep cool, refrigeration systems and refrigerated cases are embracing natural options. Natural refrigerants such as CO2, propylene glycol and even propane are replacing some of the ozone-depleting alternatives that have been used in the past and are being phased out.

Grocers are also installing refrigeration systems with more energy-efficient compressors and other components; monitoring their systems to stop leaks quickly while maximizing their cooling power.

“There are quite a few noteworthy features that retailers can expect from the latest refrigeration solutions,” says Travis Lumpkin, senior product leader, refrigeration systems for Bridgeton, Mo.-based Hussmann. “With the latest improvements in control algorithms and advancements in compressor design, system operating parameters can be better managed. The latest solutions adjust better to current conditions and loads and are more efficient as a result.”

Environmentally friendly refrigerants are also driving trends in refrigeration system design, say industry observers. Options include various CO2 systems, new distributed systems and the integration of some familiar technologies such as glycol. These solutions offer system operation enhancements and end-user savings. These savings include reduced refrigerant charge, fewer refrigerant leaks, installation savings and improved energy performance.

“Everyone is experimenting with different architectures,” say Rajan Rajendran, engineering services director for Emerson Climate Technologies, based in Sidney, Ohio. “The main thing for retailers and manufacturers is to make sure that we’re meeting the sustainability objectives, including reducing refrigerant charge, reducing heat potential and improving efficiency. We also have to make sure everything is economically feasible.”

Howell Feig, director of sales for AHT Cooling Systems USA, based in Hanahan, S.C., says there is a move toward natural refrigerants, including propane. “We believe that alternative refrigerants, which have low to no harm impact on the environment, are becoming increasingly relevant,” he says. “For many years AHT has been offering equipment with propane in other parts of the world and when it comes to sealed systems that require minimal refrigerant charge, the U.S. seems to be moving toward accepting this refrigerant option in the near future.”

He adds that aside from being environmentally friendly, propane-cooled cases use smaller amounts of refrigerant than alternative cooling methods. “There is nearly no chance of a leak because everything is fully enclosed, but even in the rare event of a leak, very little gas is emitted into the environment,” he says.

Mobility is another trend driving developments in refrigeration equipment. As retailers look to make stores more energy efficient, they also want more flexibility. Feig says that AHT’s self-contained cases can be placed anywhere there is an electrical outlet, be easily moved as needed and have simple-to-adjust configurations.

AHT’s newest model, the Manhattan, will be available in September. The unit is 83” x 40” and comes standard with LED lighting, price rails, promo sign holders and dual-temperature capability. An ultra-strong interior grid system for holiday items and a four-lid top to enhance the shopping experiences are also standard. Feig says the Manhattan is ideal for small format stores and existing stores either looking to replace narrow islands or looking to add capacity in the meat, seafood, dairy or deli areas.

In October all of AHT’s horizontal freezers will be available with an automatic defrost option. The company also plans to bring its plug-in multi-deck refrigerated case to the North American market in the near future. “This will provide retailers with another option, which can reduce installation costs, construction/install time and energy costs—all while providing the most flexibility,” says Feig.

Distributed systems and secondary coolant systems are also seeing an increase in demand as an alternative to traditional direct expansion systems, primarily for their environmental benefits.

“To achieve significant refrigerant charge and leak reduction, many retailers are looking more toward distributed systems and secondary coolant systems,” says Bruce Hierlmeier, manager of engineering for Zero Zone, Inc., based in North Prairie, Wis. “Zero Zone Edge Distributed Systems provide zoned refrigeration, where groups of cases or walk-ins are refrigerated by multiple smaller systems, with each system located very close to the equipment they refrigerate. Potential for catastrophic leaks is eliminated since each distributed system has a relatively low charge.”

Stay on top of regulations

Regulatory issues surrounding refrigerants, energy and other areas of the refrigeration business continue to be a challenge. Since regulations vary from state to state and even across different municipalities it is vital for retailers to stay informed.

“One way to stay informed is by participating in industry associations like AHRI, ASHRAE, FMI and IDDBA, to name a few,” says Henry Pellerin, director, marketing programs for Conyers, Ga.-based Hill Phoenix. “At Hill Phoenix, we have taken more of a proactive approach to helping keep customers informed.  Seven years ago we created the Hill Phoenix Learning Center to help our customers stay informed and educated on new technologies and regulatory trends. This year we [developed] a Technology, Regulatory and Trends Symposium that we have taken on the road at key locations across the country.”

Retailers are also seeking out creative, flexible and innovative display cases that provide them with the ability to present products in a way that leads to sales. Efficiency is also important. Pellerin says Hill Phoenix continues to develop new technologies that focus on operation efficiency.

“At our Barker Specialty Products by Hill Phoenix division, Coolgenix technology continues to be popular,” he says. “This is a technology that increases the shelf life of a product without adding misting systems. Using this technology, retailers don’t have to remove the product at night and use very minimal labor with trimming product in the morning, which is a tremendous labor and shrink savings. In our display case line, more than 60% of our display case orders have switched to using our proprietary Synerg-E technology, which incorporates a patented coil and advanced air flow management system that drastically reduces energy consumption.”

Maintenance avoids mayhem

Perhaps just as important as generating sales is minimizing loss. For example, even one case failure can lead to losses in the thousands of dollars. That makes proper maintenance critical. Observers say to best maintain their refrigeration systems many retailers are showing an increased interest in oil management.

“The Zero Zone Oil Management System assists in maintaining correct oil levels, reducing the potential for excessive oil circulation in the system that, otherwise, could result in evaporator efficiency loss,” says Hierlmeier. “Retailers want to avoid overfilling their systems because that can result in excess oil coating the inside surfaces of heat exchangers and reducing system efficiency.”

He adds that a significant benefit of maintaining correct oil levels is that it can significantly extend compressor life and minimize maintenance and its associated costs. Electronic control valves allow the system to run more efficiently with a higher suction pressure and lower discharge pressure.

It is also especially important to be able to identify potential problems before they become catastrophic. One difficulty in monitoring case efficiency is getting an accurate read on the case’s temperature over time.

“A thermometer will only tell you what the temperature is at that moment, if it is accurate, but there are many variables, such as how often the door is open and shut and the temperature in the store,” says Troy Tandy, president of Woodland, Calif.-based Refrigeration Innovation.

He says the company’s Thermo-Simple product line comes in a wireless version and can be integrated with a retailer’s energy management system. The system can be configured with multi-colored lighting options to indicate various temperature conditions or used in a  “no light, no problem,” mode.

Emerson’s CoreSense technology provides advanced diagnostics, protection and communication in its Copeland compressors, says Jason Prenger, Emerson’s marketing manager-food retail. “Food retailers in particular, that operate on slim margins and depend on their equipment always being operational, have to protect their investment, reduce downtime and maintenance costs,” he adds.

Observers say that retailers are also focused on lifecycle value performance.  One way they do so is by evaluating how equipment will perform in the long-term. “This is particularly important for grocers as they are looking at reducing energy consumption and potential of refrigerant leaks,” says Dustan Atkinson, product manager of supermarket systems for Heatcraft Worldwide Refrigeration North America, based in Stone Mountain, Ga. “Retailers want to be sure they are not improving one yet hurting the other.”

He explains that the HyperCore microchannel condensor coils, a standard feature on the company’s ½ to 6 horse power air-cooled condensing units, are all-aluminum coils with multiple flat tubes containing small channels through which refrigerant flows.

“The all-aluminum Hypercore microchannel condensor coils have a very robust, durable design and are very corrosion resistant,” he says, adding that the technology reduces refrigerant charge by up to 70%, leading to as much as a 40% reduction in system charge and reducing costs.

Looking forward, Atkinson says the technology will get even more sophisticated in terms of energy efficiency, durability and maintenance. “Things will just keep improving as retailers look for the best solutions for the environment and for their customers and we strive to meet those demands,” he says. 

Cool Illumination

LED lighting continues to gain ground as an efficient and low-maintenance solution for lighting freezer cases. Industry observers say that most larger grocery chains have adopted LED in freezer doors or are in the process of doing so. The smaller ones that have not are in the analysis stage. Observers add that as they better understand the benefits of the technology they expect them to follow larger chains lead.

What is driving interest?

“Energy savings is first and maintenance is second, but grocers are realizing that they can also enhance the lighting in the cases with this technology,” says Bryan Warner, vice president of sales and operations for ElectraLED, based in Largo, Fla.
While LED is now being adopted in frozen and refrigerated cases with doors, observers say open deck refrigerated cases are the next frontier.

“Today, supermarkets are using LEDs in freezer and cooler cases, primarily vertical cases, but horizontal cases are now being considered,” says James Conley, program manager for Danvers, Mass.-based Osram Sylvania.

By using LEDs in freezer/cooler cases, Conley explains that retailers can save up to 70% energy savings on lighting alone and an additional 40% of that savings can be realized by reducing the load on the compressor, depending on operating temperature of the case, as well as type and age of the compressor.

LEDs are even creating branding opportunities, according to Michael Valitchka, vice president of business development for Chicago-based FLEx Lighting. The company has developed a thin plastic panel with LED lighting that can be attached to freezer doors with suction cups. “It is clear when it is not illuminated, but bright like a neon sign when activated,” he says.
The signs are currently being tested and can be customized. “It really is a unique way to gain attention in a crowded freezer case,” Valitchka says.

Shutting the door on energy waste

One way to keep in the cold is to put a door on a case. While there were initial concerns that this energy-saving strategy would prevent impulse purchases, industry observers say there has been no impact on sales.

“We have been doing retrofits for the past three years. As our customers become more comfortable and confident that sales will not be impacted, they are starting to specify our equipment upfront,” says Rick Waldron, product manager for Remis America, based in Elkhart, Ind. The company works with many of the major refrigerated case manufacturers to offer its doors as an option.

“There are significant savings—up to 80% in compressor power for open versus cases with doors,” adds Waldron.

Night curtains are another option for containing the cold. Observers say night curtains not only save on energy costs but they can help keep product fresher.

“Loblaws in Canada would take the produce out of the cases every night, which involved labor and potential damage to the merchandise,” says John Vahman, general manager for Holly-Tech Limited, based in Oakville, Ontario, Canada. “The night curtain has eliminated the need to do that.”

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