I know only one thing AC and s are not envoirment friendly. They release too much heat and it is harmful for trees and birds. It is easy to buy AC than plant some trees,

Freons is known to deplete the ozone layer.

Freons are chemicals belonging to fluorocarbon group and are good coolants. That's why used in refrigerators and AC. However, they are environmental hazards and do deplete ozone layer. But as far as I know the new AC products do not use them.  

We get all the information n the net but the modern technology has been banning R22 freons ..

Freon is a gas which is colorless and is used in refrigerators and air conditioners. It gets compressed and this process makes it hot. When it moves down the coil, it cools down to a liquid form. It absorbs heat from outside and pushes the chilled air outside.

Frons are used in refrigeration and air conditioning. They are harmful for ozone layer.