R410A is the preferred refrigerant for use in residential and commercial air conditioners in the United States, Canada, Europe and Japan. It was developed as a environmentally friendly replacement for R22, which was considered as a contributor to greenhouse gases.
Most modern air conditioners opt for R410A refrigerant, which allows systems to operate and higher pressures, vs R22.
For installers and HVAC professionals, most will need specialized tools and equipment in order to work with R410A, for example adapters and fittings, for vacuum pumps.
As of 2010, R22 is not permitted in the United States or Canada, and has been replaced by R410A refrigerant, which is a more efficient and eco-friendly refrigerant.