R-410A: Special Handling Is Required

More and more residential and light commercial air conditioning equipment is being built with HFC-410A instead of HCFC-22. The refrigerant is being made by several manufacturers under different brand names. All carry the ASHRAE number R-410A.

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.

Common Questions

Where can I buy R-410A? All authorized distributors should have access to 410A. More than likely you will be servicing equipment with R-410. Therefore, you will want to both work with your distributor so that this refrigerant is stocked and to keep it on hand, as well to ensure you are prepared to handle these service calls when they come in.

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