“The carbon dioxide used as a refrigerant is generally of industrial or scientific grade and is typically recovered from the waste streams of industrial processes.”

– ASHRAE, Refrigerants and their Responsible Use

CO₂ (R-744) is a refrigerant option that, with the right investment in energy efficiency improvements, can be a workable solution for certain applications. CO₂ has a A1 safety classification (“lower toxicity, no flame propagation”). CO₂ performs best in cooler climates where ambient temperatures do not impact its energy efficiency.

Carbon dioxide is manufactured to meet refrigerant quality specifications via industrial gas processing and purification technology.

R-744 has unique safety and operational properties that require service technicians obtain specialized training and purchase dedicated tools.

Switching to CO₂ in existing systems is not possible without more complex, large-scale renovations and new equipment. The greater complexity can drive cost and require more downtime for retailers and other end-users. For this reason, these systems are typically only developed as part of new builds.