R421a, Drop-In R22 Replacement Refrigerant 25 LB

R-421A Frequently Asked Questions

What is R-421A?
R-421A is an ASHRAE-designated, SNAP approved non-ozone-depleting R-22 replacement consisting of R-125 and R-134a. It is the only 2-component R-22 replacement available today.

Is a TXV orifice changeout required?
No. In most cases, no change to the TXV orifice is required. Adjustments may be needed to achieve optimal performance, based on unit design. Every system has unique properties, and a technician must take these into account when retrofitting a system.

Does an R-421A retrofit require an oil change?
In most circumstances there is no need for an oil change due to the unique lubricant that is part of the R-421A formula.  This proprietary lubricant facilitates oil return in applications utilizing MO, AB and POE oil.  However, there are uniqe situations where the unit must be changed to POE.  If there is a vertical height difference of 20 feet or more between the evaporator and condenser, the system must be converted to POE.  POE oil makes it easier for the compressor to overcome the height extremity because it is lighter than MO oil.

Can a system running on R-22 be topped off with R-421A?
the simple answer is no.  If a technician were to “top-off” an R-22 system with R-421A, they would essentially be creating a refrigerant mix that is not authorized by the EPA.  It is a Federal violation to knowingly mix refrigerants.  R-421A will not operate correctly if mixed with other refrigerants.  A technician can add R-421A refrigerant to a system that contains only R-421A.

Does R-421A contain flammable hydrocarbons?
No. Unlike other R-22 replacement refrigerants, R-421A contains no hydrocarbons and is designated A1 by ASHRAE.

How does the P/T chart of R-421A compare to R-22?
R-421A has a saturation pressure-temperature dependence that is nearly identical to R-22, with a difference of less than 1% for most of the temperature range of interest.

Can R-421A be “topped off”?
Yes. Once a system has been converted to R-421A. In the event of a system leak resulting in a loss of refrigerant, R-421A can be directly added to the system with no adverse effects on performance.

What are the components that make up R-421A?
R-421A is comprised of a 58/42 blend of R-125/R-134a, and is packaged with a proprietary lubricant.

Are special gauges or equipment necessary to use R-421A?
No. Existing gauges, line sets, and other equipment designed for R-22 is compatible with R-421A.

Is R-421A approved by compressor manufacturers?
No. At this time, compressor manufacturers have not approved ANY R-22 direct replacements for in-warranty repair work.

Where can I buy R-421A?
For a list of R-421A wholesale distributors, please contact your local  Sales Representative, call 800 425-0491 or visit https://allair.net