The temperature at which a refrigerant will be able to evaporate is known as the evaporator temperature. This is usually determined by the pressure in the system.
A typical evaporator on a system using R-22 has a normal saturation temperature of about 40F, which occurs in about 68.5 pounds per square inch. This is also called the selection pressure.
Operating pressure is the amount of air that can be moved through the system at one time. It is important to understand that pressure will vary depending on the temperature and humidity of the surrounding environment.
Refrigerant R22 is an ozone-draining gas that was banned from stockholding and system topping up by EU legislation on 1st January 2016. As a result, any equipment with r22 will no longer be available to purchase or service. Rather, it will be required to be replaced with another type of refrigerant. There are many options for replacing r22, but they all have different advantages.
The condensing temperature is the saturation temperature at which a refrigerant changes from vapor to liquid; it can change depending on ambient temperatures.
It is a critical operating parameter. It determines how much heat a system can transfer from the evaporator to the refrigerant.
For most systems, 20F to 25F should be measured near the compressor and 10F at the evaporator.
The condensation temperature is also known as the bubble point. This temperature varies according to the pressure in the system, and can be calculated by subtracting the pressure from the system’s temperature.
In addition to its lower operating pressure, r22 has a much smaller impact on the ozone layer than other refrigerants. It has less of an ozone obliteration potential than refrigerant R410a, which is an HCFC.
Evaporator pressure is a big deal in refrigeration. It can make or break your system.
To get an r22 to boil (evaporate) at a temperature that has practical value for cooling air, it needs to be placed under pressure. The saturation temperature of an r22 refrigerant is -41 F at normal atmospheric pressure, so the operating pressure for your system should be in the range of 68.5 psi.
This is not an exact science, as it also depends on the relative humidity and your local climate. To get a ballpark figure on your evaporator pressure, try a simple chart online that equates the compressor vs evaporator pressure for different temperatures. If you’re looking for more specifics, contact your HVAC dealer to see if they can help. They’ll be happy to provide a more detailed analysis of your system. They’ll also be able to tell you the right refrigerant for your system and advise on any required service or maintenance.
A typical vapor compression refrigeration system has two pressures: the high-side or head pressure and the discharge or condensing pressure. The high-side pressure is the pressure created by the compressor’s exhaust valve and the metering device (such as a flow switch).
R22, the most commonly used refrigerant in air conditioning systems, has an operating pressure of 250 psi at 35 degrees C. The condensing pressure is 68 psi at the same temperature.
It is also known as HCFC, or hydrochlorofluorocarbon. It is a common refrigerant in many new air conditioning and cooling equipment. However, it is one of the ozone-draining refrigerants listed in the Montreal Protocol. In developed countries, R22 will be phased out starting in 2010, but you can still use it for service until then.