Carbon Dioxide as a Refrigerant

Newsbriefs

In response to ongoing environmental concerns with refrigerants such as HCFCs and HFCs, a naturally occurring fluid may be making a comeback:

carbon dioxide. Although CO₂ is the principal greenhouse gas, compared to most other refrigerants on a per-molecule basis it is extremely benign. According to the July 14, 2000 issue of

Global Environmental Change Report, researchers at Purdue University are testing CO₂-based refrigeration devices. CO₂ can be used in refrigeration systems only at very high pressure, but new equipment may be up to the task. An advantage of the high-pressure operation is that thin tubes can be used, resulting in compact units for portable application.