Contractors Get to Know CO2

Oct. 21, 2010
Two refrigeration contractors worked in tandem with the Kysor/Warren company to complete two recent installations of CO2 sub-critical cascade systems.

Kysor/Warren, a division of Manitowoc Foodservice, and a leading manufacturer of refrigerated display cases and refrigerated systems for supermarkets throughout North America, has received the 2009-2010 GreenChill Distinguished Partner Award from the U.S. Environmental Protection Agency (EPA).

The award was presented during a Sept. 22 ceremony following the Food Marketing Institute’s Energy and Store Development Conference in Minneapolis. Each year, the EPA presents the GreenChill Distinguished Partner Awards to organizations that have demonstrated a strong commitment to protecting the environment by reducing the harmful impact of commercial refrigeration systems on climate change and the Earth’s ozone layer. Kysor/Warren received the only award presented in this year’s non-supermarket partner category.

"The EPA is very proud to recognize Kysor/Warren with our Distinguished Partner Award this year," said Keilly Witman, Manager of EPA's GreenChill Partnership. "Kysor/Warren continues GreenChill's tradition of recognizing an advanced technology manufacturer for outstanding contributions to furthering the Partnership's mission to reduce refrigerant emissions from supermarkets. Kysor/Warren's contribution to GreenChill over the past year has been of the highest caliber, both in terms of quality and level of commitment."

In October 2009, Kysor/Warren unveiled its first naturally occurring carbon dioxide (CO2) refrigeration system with grocery retailer, Food Lion. Using a natural refrigerant, the (CO2) system lowers the global warming potential by approximately 50%, creating a significantly less harmful impact on the environment. Earlier this month, the manufacturer also partnered with Fresh & Easy Neighborhood Market, installing the environmentally friendly system into the grocer’s first GreenChill certified store in Rosemead, CA. The system is expected to reduce the impact of the store’s refrigeration on the ozone layer by nearly 70% as compared to industry standards.

In August 2010, the manufacturer was also honored with the Community Green Award recognizing it as a good steward of the environment. “As a natural refrigerant, (CO2) is a more sustainable technology,” says Travis Lumpkin, Kysor/Warren’s vice president and systems business unit leader. “The retail industry is concerned about emission control and emissions reductions in their operations, and having a natural refrigerant in the store contributes to their emissions reduction programs. If (CO2) does happen to leak, it doesn’t have any negative effects on the environment,” Lumpkin says.

The Fresh and Easy and Food Lion stores use a Kysor/Warren sub-critical cascade system. The low-temperature units are served by direct expansion (CO2). The medium temperature products in the retail space use pumped (CO2) as a secondary coolant. The low temperature products are preserved by a vapor compression cycle, with (CO2) compressors, expansion valves, and the other normal components required in a standard refrigeration cycle. “Secondary applications, by design, are traditionally less efficient, because you have additional power consumption to run a pump,” Lumpkin explains. “But because our system is already bringing the (CO2) liquid to a temperature where we can use it as a secondary coolant at the ideal temperatures of 22-23F, it makes sense to use a pump circulate that coolant to the medium temperature cases, rather than driving the temperature unnecessarily lower by use of expansion devices.”

Source Refrigeration of Anaheim, CA, installed the Fresh and Easy system with the support of Kysor/Warren experts. Bryan Beitler, vice president, engineering, Source Refrigeration, Anaheim, CA, and his installation team had heard about the Kysor/Warren system at various refrigeration industry events. They had experience working on other types of systems for Fresh and Easy stores, and were ready to apply that experience to this new system.

“Kysor/Warren’s team had put together the design concept for the equipment, and we collaborated with them in producing the drawings and engineering for the store. We incorporated their information into a set of drawings,” Beitler explains. “We worked as a team with the architect, project managers, and procurement team. We all started with a blank sheet of paper. We reviewed what they wanted to incorporate, and what had to be modified. Clear communication was critical, and contributed to the success of the project.”

Source is an expert in the design, installation, and management of mission critical refrigeration and HVAC systems. Source specializes in optimizing system performance while reducing the use of energy and impact on the environment. They have 30 branch offices and approximately 800 service and installation technicians across the U.S .

Tom Alesi, president of Atlanta Energy Specialists, Atlanta, GA, and his team installed the Food Lion cascading (CO2) system for the Food Lion supermarket in Columbus, GA. Like the Source team, they also visited the Kysor/Warren headquarters for pre-installation training. According to Alesi, the primary challenge with the Food Lion installation was in dealing with the higher pressure of (CO2). At its food preservation temperature, it’s 480 PSI. As one solution, we use K-copper, which has a thicker wall, with a maximum diameter of 1-1/8-in. It has a higher burst rating of 1000 PSI.

”The K-copper is a little bit more expensive, but the cost is balanced out by the minimal expense for (CO2), which is about one seventh the price of refrigerant,” Alesi says. “As refrigerant costs go up, (CO2) is plentiful and relatively inexpensive.”

Lumpkin says (CO2) acceptance will become more widespread, as contractors become more familiar with it, and come to appreciate its environmental and refrigerant-savings advantages.

“As with anything in human nature, you have things that are familiar, that you have trusted over time. Key questions with (CO2) are related to the pressures, alarm protocols, and troubleshooting the system," Lumpkin explains. "Once contractors become comfortable with those technical differences, it’s fairly easy. On the display case side it’s very similar to what they’re doing today. The equipment is a little bit different equipment, with special gauges that are commercially available.

"When setting superheat, the pressures are slightly different, so it’s important to be familiar with the pressure/temperature chart. On the systems side (the high side), (CO2) in a sub-critical application does require a separate refrigeration system.”