Switching from R22 to R410A and R32: what happens to old units?

Many buildings still have 15-20 year old R22 split air conditioners, VRF systems and chillers running. Owners of these units usually ask us the same question: "The unit works, but what will we do when the refrigerant runs out?" In this article, we explain the differences between R22, R410A and R32 and the realistic options for old units.

Why was R22 phased out?

R22 is a refrigerant from the HCFC group that harms the ozone layer, so it has been phased out step by step under the Montreal Protocol. Türkiye also followed this schedule and ended the import of R22 and its use in new units.

This does not mean that existing R22 units must be removed immediately. Units can be used as long as they keep running. The problem arises in the event of a leak or compressor failure: there is no new R22 on the market, and the remaining stocks and reclaimed refrigerant are both limited and expensive.

What is the difference between R410A and R32?

R410A is a blended refrigerant that replaced R22; it does not harm ozone but has a high global warming potential (GWP). R32 is a single-component refrigerant, one of the components of R410A, with roughly one third of the GWP. Today, most new split air conditioners are made with R32.

R32 being in the mildly flammable (A2L) class requires additional rules during installation and service. It is used safely when working with suitable equipment and trained technicians, but caution is needed in confined spaces without ventilation where soldering with an open flame is done.

Can R410A or R32 be charged into an R22 unit?

No, R410A or R32 cannot be charged into a unit designed for R22. R410A and R32 operate at much higher pressure; the compressors, heat exchangers and valves of R22 units are not designed for this pressure. In addition, the mineral oil in R22 systems is not compatible with these refrigerants.

Be cautious if you hear someone say "we charged the R22 unit with a new refrigerant and it works." A unit running on the wrong refrigerant can suffer compressor failure in a short time and poses a safety risk due to pressure.

What are the options for old R22 units?

There are three realistic options for an R22 unit: keep it running as is while keeping it leak-free, switch to a suitable retrofit refrigerant, or replace the unit with a new-generation system. The right choice depends on the age, condition and criticality of the unit.

01Keep it leak-free and keep running it

If the unit is sound and there is no refrigerant loss, it can be run for some more time with regular maintenance and leak checks. This option is the most economical in the short term, but the decision returns at the first major fault. It makes sense to use this time to plan the budget for the new system.

02Switching to a retrofit refrigerant

For R22 systems there are ozone-safe retrofit refrigerants that can be used with the existing oil or after an oil change. In this process, the old refrigerant is fully recovered, the oil is changed if necessary, the filter drier is renewed, the system is evacuated, and the new refrigerant is charged using the method recommended by the manufacturer. Retrofit refrigerants usually bring some loss of capacity and efficiency; the expansion valve setting must also be readjusted.

A retrofit works as a stopgap solution for a few years, especially in large systems that are not easy to replace, such as chillers or cold rooms. Retrofitting a unit with a tired compressor and a chronic leak problem, however, is generally a waste of money.

03Replacing with a new-generation system

If the unit is over 15 years old, breaks down often, or its compressor will need replacing, switching to a new-generation unit is often the right decision. New inverter units consume noticeably less energy at the same capacity; the picture becomes clear when you consider the size of the difference together with the losses we describe in our neglected air conditioner and energy consumption article.

What information should be considered when deciding?

Making the right decision for an R22 unit is possible with a few measurements and records that show the real condition of the unit. A guess-based decision leads either to unnecessary investment or to repeated faults in a short time.

• Age and total operating hours of the unit
• How many times refrigerant has been added in recent years and whether the leak has been found
• Compressor current and winding insulation value
• Suction and discharge pressures and superheat values
• Availability of spare parts
• Criticality of the area the unit cools

When this information is assessed together, it becomes quite clear whether the unit can keep running safely for a few more years.

Can old copper pipes be reused?

An old R22 pipeline can be reused in a new R410A or R32 unit under some conditions, but this decision should not be made without an on-site inspection. Pipe diameters must match the values of the new unit, wall thickness must withstand the pressure of the new refrigerant, and the insulation of the line must be intact.

A line to be reused is put through a special cleaning process to remove the old mineral oil and dirt inside. Flare connections are redone to suit the new refrigerant; for some diameters the flare dimension is also different. A nitrogen pressure test and vacuum are then applied. For lines running inside walls that are hard to replace, this method saves substantial labor. Some manufacturers also offer special unit series intended for reusing R22 lines.

What will happen to the future of R410A?

Because of its high GWP value, R410A is among the refrigerants being phased down under F-gas regulations. This does not mean existing R410A units cannot be used; refrigerant for service will continue to be available, but its price is expected to rise over time.

For a new investment, choosing units that use R32 or a lower-GWP refrigerant is a safer path in the long run in terms of refrigerant cost and regulation. Natural refrigerants such as propane (R290) are also becoming common in heat pumps and some monoblock units. When choosing which type of unit suits your building, a heat load calculation must always be done.

Every operation on the refrigerant circuit, that is, refrigerant recovery, retrofit, leak detection and charging, must be performed by an qualified and certified technician. At YOİ Mühendislik, in our refrigerant leak and charging work, we recover the old refrigerant without releasing it into the atmosphere, measure the condition of the unit, and tell you in writing whether a retrofit or a new unit installation is needed. The decision and cost are determined at the site survey, with the unit seen on site.