“Our Protocol CO2 is a future-proof refrigeration solution built for performance, flexibility and sustainability,” Hussmann says on its website.
Part of the company’s Evolve Technologies Portfolio, the Protocol CO2 system is available in capacities from 90–400MBH (7.5–33.3TR/26.4–117.2kW). It is designed specifically for indoor commercial installation and is available in multiple pre-engineered configurations to meet diverse operational needs. An optional heat reclaim feature enhances system efficiency and supports compliance with Title 24 building efficiency standards for installations in California, the manufacturer noted.
The new unit, which is available now, is the latest addition to the Hussman’s Protocol range, first introduced in 1993. In late 2024, Hussmann added its first CO2 outdoor condensing units to its commercial and industrial refrigeration portfolio.
Hussmann has sold six Protocol CO2 units to date, Michael Lehtinen, the company’s Senior Product Leader for CO2 Solutions, told NaturalRefrigerants.com. The first unit is already operational, with four more expected to be installed at the same location over the coming months. The sixth unit will be shipped to separate location in July, he added.
“Our Protocol CO2 is a future-proof refrigeration solution built for performance, flexibility and sustainability.”
Hussmann
Efficient operation
Key performance features include three to five variable-speed medium-temperature scroll compressors with direct vapor injection, enabling precise capacity modulation, reduced discharge temperatures and higher efficiency. For low-temperature applications, the system uses two or three digital scroll compressors for fine-tuned energy control. All compressors are supplied by Copeland.
System control is handled via an integrated Copeland variable-speed drive for the lead compressor and XP Pro Pack controller hardware, delivering advanced diagnostics and energy management. An economizer is also integrated to reduce gas cooler return temperatures, further improving performance. Additional components from Temprite and Castel support system reliability.
Serviceable design
The distributed rack system offers a modular design that simplifies installation in partial remodels or gradual transitions to natural refrigerants. Its quiet, low-vibration operation is it well suited for sensitive areas such as supermarket back rooms.
To simplify installation and maintenance, the rack uses iron/copper piping to eliminate the need for certified welding and configuration ensures easy access to electrical and mechanical components.
“With removable panels on all sides, an ergonomic layout, and an intuitive touchscreen interface, this system ensures fast, user-friendly maintenance,” Hussmann says on its website.
Lehtinen will be participating in the Refrigeration Market Trends session on the first day of the AMTO America Summit 2025. The two-day event will take place June 11–12 in Atlanta and is organized by ATMOsphere, publisher of NaturalRefrigerants.com.
