Contractors and technicians need to know that R-410A can only be used in equipment designed for R-410A. It cannot be used to retrofit existing R-22 equipment due to significantly higher operating pressures. Furthermore, special service equipment is required, such as a high-pressure manifold gauge set, a high-pressure recovery unit, and a high-pressure recovery tank.
Because of its enhanced properties, R-410A systems operate differently than R-22 systems.
Due to 410A’s higher pressure, most system components have been redesigned with increased wall thickness.
When servicing this equipment, make sure you use reversing valves, expansion valves, filter-driers, and other components specifically designed for R-410A.
In addition to increased wall thickness, the expansion valve flow area required to provide the same tonnage as R-22 will be about 15% smaller.
What about the brands of R-410A? Puron® and Suva® 410A are marketing brands for ASHRAE R-410A. Puron is Carrier Corp.’s brand name and Suva 410A is the DuPont brand name. Both have the same chemical composition and can be used interchangeably.
Can R-410A be used to retrofit existing R-22 equipment? No. Because of the much higher discharge pressure and cooling capacity, R-410A should only be used in equipment designed for it.
Do I need different service tools to work on R-410A systems? Yes. Because of the higher pressure, you should use manifold gauge sets designed for R-410A. In addition, you should use a recovery unit and tanks designed for the higher pressure of R-410A. Recovery tanks should be specified as DOT 4BA400 or 4BW400.
What type of lubricant should be used with R-410A? Use a high-quality POE (polyolester) specified by the compressor or system oem.
Will R-410A systems have different components than R-22 systems? Yes. Because of the higher pressure for R-410A, most system components have been designed with increased wall thickness. In addition, expansion valves specifically designed for R-410A capacity should be used.
Is R-410A a blend refrigerant? Yes. It is a blend of two refrigerants, HFC-32 and HFC-125 (50/50 wt%), that performs very much like a single-component refrigerant.
How should I charge R-410A? For optimum performance, R-410A should be removed from the cylinder as a liquid.
Bateman is senior engineer for DuPont Suva Refrigerants. For more information, contact DuPont at 800-235-7882 or www.suva.dupont.com.
Publication date: 02/05/2001