Hole in ozone layer is discovered over Antarctica in 1985.Because of this hole, Ultraviolet light can reach the earth and harm both the humans (skin cancer) and plants. In 1987, USA and other developed nations signed Montreal Protocol as an effort to protect ozone layer by reducing the use of CFC and HCFC .In 1993, the Schedule to end CFC and HCFC are announced. The production of CFC ended on 1996 and all ozone depleting substances (HCFC including R22) will face a complete ban on 2030.
Pressure temperature chart or PT chart is one of the most important tool to evaluate system performance or diagnose problems.Technicians can use it along with metering
gauges to check the proper functioning of Air conditioner (AC) Systems .Below you can see the PT charts of most important refrigerants :
Why R22 is replaced with R410A?
Its performance is similar to R22 and it does not contain chlorine and hence it is less damaging to Ozone layer.