What refrigerant can top off R-22?

Author: Mary Zemlak MD  |  Last update: Wednesday, June 17, 2026

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

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

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

What refrigerant is compatible with R-22?

Freon™ MO29 refrigerant: Extends system life using the same equipment as R-22, so a system with an R-22 leak does not need to be completely replaced or upgraded.

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.

Can I put R-410A in a R-22 system?

The pressure can become high enough for parts of the system to rupture. 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.

Best replacement for r22 refrigerant gas in refrigeration and air-conditioning

What would happen if R-410A was added to an R-22 system?

A NJ Tech Explains. The answer: No. Putting R-410A refrigerant into an AC unit that was designed to use R-22 will cause the unit to die soon after it tries to run.

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.

Can you put 422b on top of R-22?

No. 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.

Can you put 427A on top of R-22?

Can I mix Forane® 427A and R-22? Mixing refrigerants is not recommended as it creates a new refrigerant that is not EPA approved. In addition, it contaminates the R-22. Proper calculation of superheat and subcooling becomes extremely difficult, which could result in damaging the compressor.

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.

What refrigerant is drop in replacement for R-22?

The information below will try to dispel some of these myths. Arkema recommends using Forane® 427A (R427A) - The EASY RETROFIT™ for your r-22 retrofit solution. When it comes to drop-ins, the truth is that there are none. The hope of “drop-in” refrigerants has become common over the years.

Will a Txv rated for R-22 work with R-410A?

"Hey Dan, do I need to change the TXV valve when switching the outdoor condenser from R-22 refrigerant to R410A?" Yes, you are going to have to change out the TXV. Why? Well, R410A works at a different temperature and a different pressure than R-22. If you don't change it then it's not going to boil off correctly.

Can I put R134a in a R-22 system?

No, the compressor will fail. These two refrigerants have very different properties. One of R22 and R134a is high pressure and the other is low pressure. They don't mix chemically and don't have the same boiling point, leading to inefficiencies and eventual compressor failure.

What refrigerant is compatible with R-22?

  • Also Acceptable: R427A, R404A, R407C.
  • Also Acceptable: R422D, R427A.
  • * Note: If compressor is being replaced as part of the service call on a small system, install a POE compressor and retrofit to the better capacity/lower GWP blend.

Can you put MO99 on top of R-22?

No. Freon™ MO99 should not be used to top off R-22 systems.

Can R-22 be topped up?

Having said that, some unscrupulous contractors will top up R22 with a similar refrigerant like R438a in an attempt to save themselves time and money. You simply cannot use an alternative refrigerant to top up a system charged with R22 and no amount of “she'll be right, mate” will ever change that.

Can you top off R-22 with 410A?

Never mix R-22 and R-410a.

Is 427A a good replacement for R-22?

R-427A has similar capacity, efficiency, and mass-flow rate to R-22, making it an easy retrofit option for large, medium, and small air-conditioning and refrigeration systems.

Can you put 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.

Can you mix 438A with R-22?

R-438A should not be mixed with any other refrigerant! Demand Cooling™ is required for low temperature applications. 5. When retrofitting from R-22 to R-438A, the expansion valve will likely not require replacement; however, it is recommended that the valve loadings be evaluated to verify that they are adequate.

How to replace R-22 with MO99?

[blog-external] – popular
  1. Establish baseline performance with existing refrigerant. ( ...
  2. Remove all the old (R22 or other) refrigerant from the system into a recovery cylinder. ...
  3. Replace the filter drier and critical elastomeric seals/gaskets.
  4. Evacuate system and check for leaks.
  5. Charge with ISCEON® MO99.

Can I replace R-22 with R32 refrigerant?

Compatibility: R32 is compatible with existing air conditioning systems that use R22 and R410A, making it a suitable alternative for retrofitting existing systems. However, it's important to consider compatibility with the specific system and components before retrofitting to R32.

Can you use old R-22 lines for 410A?

When you replace an air conditioner or heat pump and upgrade from R-22 to R-410A, the ideal solution is to replace your refrigerant lines. This is because the mineral oil used in R-22 systems is not compatible with the new R-410A refrigerant and oil.

Can R-454B be retrofitted into existing R-410A or R-22 systems?

ACHR NEWS: As a mildly flammable refrigerant, R-454B can't be retrofitted into existing R-22 and R-410A systems.

Previous article
How do you remove film after mopping?
Next article
Which brand is leading in refrigerator?