ATLANTA - Guidance on the use of carbon dioxide (CO2) has been added to the American Society of Heating, Refrigerating and Air-Conditioning Engineers' (ASHRAE) 2006 Handbook, Refrigeration. Because of its good environmental properties and relative safety, there is renewed interest in it as a refrigerant. Carbon dioxide was used in the early stages of refrigeration but fell out of favor with the development of halocarbon refrigerants.

The handbook, which covers refrigeration equipment and systems for applications other than human comfort, includes information on cooling, freezing, and storing food; industrial applications of refrigeration; and low-temperature refrigeration. Primarily a reference for the practicing engineer, the volume is also useful for anyone involved in cooling and storage of food products.

"CO2 is a refrigerant with a high coefficient of performance," said Ron Vallort, a consulting engineer from Chicago who specializes in refrigeration. "Some people hesitated to use CO2 because it operates under a higher pressure and produces lower temperatures than are usually needed in some industries. But it is now coming back into vogue as a natural refrigerant with no ozone depletion potential and very low global warming potential."

Other additions to the volume include: A new chapter, "Refrigerant Containment, Recovery, Recycling, and Reclamation;" chapter 10 has extensive updates, new geometric shape factors, and a new section comparing freezing time estimating methods; chapter 13 has new material on heat gain from cooler floors and coil defrosting; chapter 46 has new discussions on self-contained versus remote systems, energy efficiency, storage rooms, and interaction with supermarket air conditioning systems; and chapter 47 has new content on refrigerated cabinets, vending and ice machines, and energy efficiency.

Publication date: 07/03/2006