R290

R-290 is the refrigerant designation for propane, a hydrocarbon used as a natural refrigerant in a variety of cooling systems. It is widely adopted as a low global warming potential and zero ozone depletion potential alternative to many HFCs and HCFCs.

It has chemical formula C3H8, a boiling point of approximately -42°C at 1 atmosphere, and a global warming potential of 3 with an ozone depletion potential of 0. Because of its flammability, ASHRAE classifies R-290 as an A3 refrigerant, requiring careful design, installation, and handling.

Applications include domestic refrigerators, freezers, commercial display cases, and some heat pumps and small air conditioners. R-290 is used as a drop-in or retrofit option where permitted by standards, and it is common in new equipment aimed at improving energy efficiency and reducing environmental impact.

Safety and design considerations: due to flammability, equipment must be explicitly designed for hydrocarbon refrigerants, with proper venting, leakage control, and electrical safety. Servicing should only be performed by trained technicians using approved tools and procedures, and refrigerant charges should follow manufacturer specifications and applicable codes.

Regulatory and environmental aspects: R-290’s very low GWP makes it attractive under international and regional schemes to phase down high-GWP refrigerants. Its use is subject to safety regulations and regional restrictions on charge size and equipment standards, which vary by country.