Can you put 407C on top of R-22?

Author: Elissa Fadel  |  Last update: Sunday, April 12, 2026

Mixing R22 with R407C According to the 609 EPA rule, mixing refrigerants is illegal and anybody caught doing so will be heavily fined.

Can you put R-407C on top of R-22?

R-407C should be used only in systems that currently use R-22. It should not be mixed with R-22 or any other refrigerant. 5. The capacity of the existing R-22 thermal expansion valve (TEV) will be approximately the same when using R-407C.

What refrigerant can I use to top off R-22?

Freon™ MO99 can be used to retrofit R-22 heat pumps .

Will a R-22 TXV work with 407C?

Air handlers with R-22 coils and thermal expansion valves will operate with R-407c at approximately 6% lower capacity than the published R-22 performance.

What freon can be mixed with R-22?

So… what refrigerant can be mixed with R-22? None. You can't mix refrigerants.

I Justify My Method of Retrofitting R407C into R22 Systems

Can 407C replace R-22?

Features and Benefits. Freon™ 407C has been a popular R-22 replacement because of its properties, which include: Similar cooling capacity, energy efficiency, and pressures as R-22 in systems. An ability to be topped off after a leak, multiple times, with minimal impact on system performance.

What happens if you mix R-22 with another refrigerant?

At the very least, leaks will occur. Mixing refrigerants is not an option either. This will contaminate the system, and the R22 will not evaporate under the higher suction pressure that R410A requires.

Are 407C and R-22 pressures the same?

Heating mode The compressor pressure ratio of R-407C was 0.7% to 9.3% higher than R-22 for the two heating mode test conditions.

Is R-407C banned?

R407C will, however, be phased out in 2025 in systems with less than 3kg charge. R410A air conditioning systems with charges greater than 3kg – including most VRF applications – are not affected. Systems with less than 3kg charge will be banned from 2025, with equipment using R32 an alternative option.

Does 407C use the same oil as R-22?

R407C does not contain the chlorine, necessary for the dissolving of mineral oils, used with R22. It has therefore been necessary to develop oils, which are compatible with the new refrigerants. They are known as Polyolester or POE oils.

What is the best replacement Freon for R-22?

Freon MO99 is the closest capacity match to R-22, compared with most other no-oil change refrigerants.

What is a drop-in substitute for R-22?

R-421A is a drop-in replacement for R22 systems. With this refrigerant there is no need to change the oil. Simply recover the R22 and recharge with R421A. Experiencing R421a problems? Read this guide.

Can you drop MO99 on top of R-22?

There is no such thing as a “drop in” replacement for R-22. Mixing refrigerants is not recommended. R-22 replacements should not be used to top off R-22 systems. R-22 should be recovered using appropriate equipment and managed according to U.S. EPA guidelines specified in Section 608 of the U.S. Clean Air Act.

Is R-407A a drop in replacement for R-22?

R-407A is a close match to R-22's capacities and flow rates, making it well suited as a retrofit for R-22 in supermarket and food storage applications. Additionally, R-407A is one of the more energy efficient R-22 retrofit options available for refrigeration applications.

What is the capacity loss of R-22 to 407C?

The best replacement for R-22 Freon is usually R-407c. It has a very low loss in capacity (0 – 5%) relative to R-22 and is less expensive than many other R-22 replacement refrigerants. If a system has R22 in it already you cannot use a replacement refrigerant to simply add to the R22.

What is 407C refrigerant compatible with?

R-407C can be used to retrofit existing R-22 systems in positive displacement, direct expansion refrigeration, and air conditioning equipment. R-407C should not be used in centrifugal chillers or other equipment that uses a flooded evaporator, due to its high temperature glide.

Can you put 407C on top of R-22?

Mixing R22 with R407C

According to the 609 EPA rule, mixing refrigerants is illegal and anybody caught doing so will be heavily fined. Although you may this restriction is primarily political we would like to give you a basic education to explain the two most devastating effects of such action: To the environment.

Is 407C a good replacement for R-22?

R-407C has thermodynamic properties that make it a "look alike" replacement for R-22, with compressor capacities and system pressures and temperatures that are similar.

Why is R-22 banned?

Because R-22 depletes the ozone layer, production and import was further limited in 2010. In 2020, R-22 will no longer be produced or imported. After 2020, only recovered, recycled, or reclaimed supplies of R-22 will be available. The production (not use) of R-22 is being phased out.

Can you top off 407C?

Freon™ 407C can be topped off after a leak, multiple times, with minimal impact on system performance.

What is the difference between R-22 and R-407C?

The refrigerant R407C is used as a replacement of refrigerant R22 due to similar operation properties for the two refrigerants. The experimental results displayed that the R22 refrigeration effect is higher than those for R407C, and the R407C coefficient of performance COP is lower than those of R22.

What is the replacement for 407C?

Opteon™ XP20 (R-449C) refrigerant is a hydrofluoroolefin (HFO) option that replaces R-22 and R-407C in residential and commercial air conditioners, as well as direct expansion chillers. It has similar performance and properties to R-22 and R-407C and can be used in both retrofit and new equipment.

How much does it cost to convert R-22 to R-410A?

How much will an R-22 to R-410A conversion cost? The actual cost will depend on many things, including where you live, but most of the time R-22 conversions start at around $2,000 and go up from there. The higher end of that range is somewhere around $4,500 to $4,600.

Is it illegal to recharge AC with R-22?

As of January 1, 2020, production and import of R22 refrigerant will be illegal in the United States. Of course, continued use of your air conditioner (AC) or heat pump system using R22 refrigerant is allowed.

Is MO 99 a good replacement for R-22?

Of all the "no oil change" replacement refrigerants, Freon™ MO99™ offers the closest performance match to R-22. Freon™ MO99™ has compatibility with all traditional and new lubricants, including mineral oil (MO), polyolester (POE) oil, and alkylbenzene (AB) oil.

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