The reasons for which chlorine-containing agents are being phased out result from the discovery of certain phenomena occurring after such agents have been released to the atmosphere. When released from the installation, a molecule of an ozone depleting substance travels as far as the stratosphere (15 ÷ 50 km above the earth). Under the influence of UV radiation, the process of photodissociation takes place, where a chlorine atom separates from the refrigerant molecule, and breaks the ozone molecule. This reaction creates: chlorine oxide + oxygen molecule (Cl+O3=ClO+O2) is formed, then chlorine oxide reacts with another ozone molecule (ClO+O3=Cl+2O2), etc. It is estimated that a single chlorine atom can destroy 10 ÷ 100,000 ozone particles.

The Fujitsu devices which are currently being launched on the market use: R407C and R410A refrigerants whose ozone depletion factor equals 0 (they do not contain chlorine atoms).

The basic differences are briefly described in the table below: