As the demand for refrigeration systems in cold storage facilities increases, packaged refrigeration units using low-charge ammonia (R717) or CO2 (R744) are evolving to become more scalable and economically viable, requiring minimum on-site labor during installation.
But which refrigerant should a cold storage operator use in these units?
Evapco, a Maryland (U.S.)-based OEM of natural refrigerant systems and components, showcased both low-charge ammonia (Evapcold penthouse refrigerators and chillers) and transcritical CO2 packaged systems at the IIAR Conference and Expo, held March 12 to 15 in Long Beach, California. A longtime provider of ammonia systems, EVAPCO now sells R744 via its Evapco LMP subsidiary, which it purchased a year ago.
The increasing demand for packaged systems is linked to the significant influx of investment into cold storage infrastructure, which is fueled by venture capital and real estate investments, noted Kurt Liebendorfer, Vice President of Evapco, in an interview at the conference.
Packaged units offer enhanced efficiency and cost-effectiveness, making them more appealing to a broad spectrum of end users. “Low-charge R717 and R744 transcritical systems have a common ground in cold storage facilities,” he said.
As to which type to adopt, in general “it’s just a personal preference.” said Liebendorfer. However, the technical aspects of cold storage facilities, and thus the technology evaluation process, can be complex, depending on the size, temperature, and location of the facility.
“While low-charge R717 systems are known for their high energy efficiency and adaptability in large facilities, R744 systems offer safety benefits and ease of use, particularly for new market entrants, especially those who are not familiar with ammonia systems,” said Liebendorfer.
In addition, Liebendorfer highlighted that “In an R717 refrigeration system, a low-grade heat is typically reclaimed and utilized for moderate dehumidification and other low-temperature applications; it can contribute to energy savings when used effectively.” On the other hand, an R744 refrigeration system can offer more heat recovery since it produces higher-grade heat, he noted. Hence, R744 systems can be used for more energy-intensive applications, such as space heating or water heating.
Evapco’s SelectTech controls, displayed at the IIAR conference.
New ‘split’ approach
Evapco now offers a new “split” ammonia packaged system that separates the evaporators from the package, linking them via piping to various parts of a facility. An ongoing project in Nevada, U.S., is Evapco’s first installation of this architecture.
Currently, “the project is in Phase I, where only two evaporators are present in the penthouse, but we aim to double the size of the current system by increasing the number of evaporators from two to four and creating a distributed evaporator system,” Liebendorfer said. The distributed evaporators, spread out across the facility, will potentially lead to more efficient cooling and better performance. This development shadows some advantages of CO2 refrigeration systems, such as large capacities and minimized controls.
In the controls arena, last year Evapco announced the formation of Evapco Select Technologies following its acquisition of Select Technologies, a manufacturer of automation machinery based out of Belmont, Michigan. The acquisition addresses the increasing market demand for advanced control systems for food processing and cold storage facilities. These control systems aim to enhance the performance of systems and improve their reliability.
Evapco showcased the SelectTech Controls at its IIAR booth.
“While low-charge R717 systems are known for their high energy efficiency and adaptability in large facilities, R744 systems offer safety benefits and ease of use, particularly for new market entrants, especially those who are not familiar with ammonia systems.”Kurt Liebendorfer, Vice President, Evapco