In 2010 environmental protection agency passed a law that air conditioner manufactures should not prepare the unit which runs on R22 refrigerant. As R22 refrigerant is harmful for the health of the people and has hazardous to the environment.

Owners who need to maintain the R22 refrigerant system would end up paying twice the cost of new air conditioning system.

All the HVAC systems which are manufactured use R410a refrigerant instead of R22 refrigerant. R410a is safer for the environment. However this refrigerant was not compatible with ozone depleting refrigerant oil.

In the later part of the 2010 most of the AC manufactures started producing the system which does not run on any refrigerant these systems are called as dry charge systems.

The purpose of the manufactures was to provide simpler and less expensive replacement of the central air conditioners to the owners.

A dry charge system replaces your outdoor compressor with a dry R22 outdoor compressor. The owner will not incur the expense of replacing indoor unit and refrigerant pipes. Now a day’s R22 systems are called as dry charge systems.

R22 refrigerants are still used for repairing and servicing. A manufacturer can buy a dry charge system and call a HVAC professional to add R22 refrigerant to the system.

A dry charge system will have following disadvantages

1. If you want to add the refrigerant to the system the cost will be increasing every year as R22 is not commonly used.
2. A dry charge air conditioner is least energy efficient.
3. Parts and the compressor warranty of the outdoor unit is less than other system.
4. If you want to replace the dry charge system than all the components should be replaced so it has high replacement cost.

Looking at these disadvantages of the dry charge system it is not a recommended to buy a dry charge system it will be more preferable to change the entire system and buy a new system running on R410A refrigerant which will be highly energy efficient and more environmental friendly.