Kitchen Designs

The Operating Pressure of R22

R22 (hydrochlorofluorocarbon) is a refrigerant that has been used for decades in air conditioning and refrigeration systems. However, it is slowly phasing out.

There are a number of alternatives to r22 that have been developed and tested, including R407C and R410A. Choosing the right refrigerant can help to lower system costs and improve system performance.


R22 (hydrochlorofluorocarbon 22) is a refrigerant that is used in a lot of appliances and equipment in homes, apartments, businesses, and industrial worksites. It is being phased out because of its harmful effect on the ozone layer.

The normal operating pressure for r22 is between 260 psig at 120 degF and 76 psig at 45 degF. The high-end pressure is measured at condensing temperature and the low-end pressure is measured at evaporator saturation temperature.

There are other sources that give lower low-side vapor line pressures for R22. This is a common old-school rule of thumb that assumes indoor wet bulb temperatures and outdoor ambient temperatures that are similar.

The low-side vapor line pressure is also affected by the amount of heat load on the system. If the system has high heat loads, then the low-side vapor line pressure increases significantly. This can lead to poor airflow and compressor performance.


The pressure of r22, the refrigerant used in air conditioners and refrigerators, is affected by the temperature. The liquid vaporizes into gas when it comes into contact with any warmer material, which is why a thermometer at the cylinder valve outlet reads -42degC (at 0 bar gauge).

On a 65-degree day, the low side of a compressor running on R-22 is about 60 psig. However, this can vary by indoor wet bulb and outdoor ambient temperatures, where higher heat loads increase the vapor line pressure.

During normal operation, the low side or suction line pressure should be about 75 psi. This can be determined by using a service chart and subtracting 45 degrees from the incoming air temperature.


R22 is a relatively low density refrigerant that can be used in older HVAC systems. However, it is slowly phasing out and will soon be obsolete. Fortunately, there are other more environmentally friendly options available.

Compared to R22, R410A is a higher pressure refrigerant that offers greater capacity, efficiency and lower cost. It also has a much lower ozone depletion potential.

As a result, many air conditioning companies have switched to using R410A for most of their systems. This allows them to use thinner compressor casings and pipes, as well as a high-pressure exhaust valve.

The operating pressure of r22 is affected by the density of the liquid and vapour inside the cylinder. The liquid density at -69degC is 1.49 g/cm3. In contrast, the gas density of r22 is 3.66 kg/m3.


When using a refrigerant such as r22, it is important to ensure that the operating pressure of the system is correct. This will help avoid the need for expensive repairs and replacements of the air conditioning unit.

The best way to achieve this is to use a gauge test gauge and measure the psi on the low and high side of the system. These can be obtained from most HVAC supply houses.

As a general rule, you want around 250 psi on the high side and about 70 psi on the low. This will help prevent damage to the compressor and air handler.

In addition, you need to make sure that the tool you are using is designed for the R22 pressure that is being used. This will prevent damage to the tool and the safety of yourself and others.

Leave a Reply

Your email address will not be published. Required fields are marked *