What Happens If You Put R410A in an R22 System?

One sign that it’s time for an AC replacement is when your system still uses R22 refrigerant. Also known as Freon, R22 was banned due to its contribution to ozone layer depletion and ecological harm.

Freon is becoming scarcer and more expensive as a result. The new standard, R410A, is more environmentally friendly but cannot be substituted for R22 refrigerant. Below, we’ll explain what happens if you put R410A in an R22 system and what your options may be.

If you haven’t yet replaced your outdated air conditioner or are concerned about the cost of doing so, we’ll review key information on what you may want to do.

R410A Systems Run at a Different Pressure

Compared to an R22 system, an R410A air conditioner runs at a higher pressure. These systems operate at about 130 pounds per square inch (psi). In AC mode, an R22 evaporator coil will run at about 70 psi. Therefore, newer systems run at nearly double the pressure, assuming they’re operating under the same conditions.

Since R410A refrigerant is charged under higher pressure, charging an R22 system with it will increase the force within the coolant lines. 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.

An HVAC System Must Be Retrofitted

Not only do these two operate at different pressures, but the lengths of the refrigerant lines are different as well. An R22 condenser is designed for a 15-foot line set. However, an R410A refrigerant system has lines of 25 to 50 feet in length. To use the new refrigerant, an older system must be retrofitted. The system must be cleaned and flushed out and then purged with nitrogen; any remaining chemicals or contaminants are then removed.

A new refrigerant line set, filter drier, and thermostatic expansion valve must be installed. Several other steps must be completed before the system can be recharged with R410A refrigerant.

Mixing and matching components is generally not recommended. Matching an R22 coil with an R410A condensing unit is not possible with an outdoor heat pump. An old coil brazed with tin and antimony should never be reused–this process was discontinued in the 1950s, so the system would probably be too old or worn out anyway.

R410A vs. R22

These two types of refrigerants will make your home’s air cooler but should not be used as substitutes for each other because of some major key differences:

Chemical Composition

  • R22 (chlorodifluoromethane): R22 is an older refrigerant that contains hydrochlorofluorocarbons (HCFCs). Due to its ozone-depleting potential, its production and import have been phased out in many countries, including the United States.
  • R410A (difluoromethane/pentafluoroethane): R410A is a hydrofluorocarbon (HFC) refrigerant. It does not contain chlorine and is considered ozone-friendly. R410A has become more widely used as a replacement, not a substitute for, R22.

Ozone Depletion Potential

  • R22: R22 has moderate ozone-depleting potential, and its use has been restricted to reduce environmental harm.
  • R410A: R410A has zero ozone depletion potential, making it the more environmentally friendly option.


  • R22: While R22 is effective, it is less energy-efficient than newer refrigerants.
  • R410A: R410A is known for its higher efficiency and better heat-transfer properties, contributing to improved system performance.

Should I Retrofit or Replace My Aging AC System?

If you still have an R22 system and it has no leaks or major issues, you don’t have to replace it. But while retrofitting might be an option, it’s not going to save you money. This project costs thousands of dollars–perhaps not less than installing a new air conditioner altogether–given the parts, expertise, and labor needed to perform a retrofit.

Consider the potential for future repairs with an older system as well. Installing a new AC avoids repair calls and increases efficiency. Therefore, when faced with the choice of retrofitting or replacing a unit, a replacement is typically more cost-effective in the long run. You’ll also avoid the result of accidentally putting R410A in an R22 system ever again.

Olympia-area homeowners rely on Black Hills for professional HVAC installation and replacement. We can help decide if repairing or replacing an aging air conditioner is a better idea based on a number of different factors.

Our staff is trained to install the latest equipment, including ductless mini-split air conditioners. In addition to properly installing high-quality, efficient ACs, we specialize in repair and maintenance. For assistance, contact us online or call 888-688-7358.