Saturated Refrigerant: Need to Know Critical Facts

What is saturated refrigerant

The temperature of “saturation” is calculated by identifying the observed pressure on the P-T card and measuring the temperature associated with it.

If you can accurately detect temperature at one of these three locations, P-T link is used to determine the “saturation” pressure by identifying the pressure that corresponds to the reported temperature. The refrigerant within vapour/liquid state is known to be the refrigerant kept in the condenser or evaporator coils.

It is only relevant when utilising your PT chart like a troubleshooting tool. The refrigerant is said to be saturated when it exists in both a liquid and a vapour state.

What does saturated mean in HVAC

By detecting the measured pressure on the P-T card and measuring the temperature associated with it, the temperature of “saturation” is computed.

In the HVAC/R industry, the term “saturated” or “at saturation” refers to refrigerant which is in the process of transitioning from liquid to vapour in the evaporator or vapour to liquid in condenser.

It is required to check a series of gauges or use a PT (Pressure-Temperature) table to determine the temperature that corresponds to a specific refrigerant and pressure. This is referred to as the saturation temperature.

How do I know if my refrigerant is saturated

The saturation temperature of a refrigerant is the temperature at which it transitions from a liquid to a gaseous state.

The “saturation” temperature is determined by locating the measured pressure on P-T card and measuring the related temperature.

This also means that if you can properly measure temperature at either of these three sites, you can use the P-T
connection to identify the pressure that corresponds to the reported temperature and calculate the “saturation” pressure.

What is saturated refrigerant temperature

The refrigerant’s saturation temperature is the temperature at which it transforms from a liquid to a vapour state. Its boiling point is the same as its saturation temperature.

When the superheat is too low, the evaporator outlet is extremely close to the point where all the refrigerant is finally evaporated. If this happens, liquid refrigerant may be forced back into the compressor, causing significant damage.

The liquid refrigerant gets completely evaporated much before it enters the evaporator outlet whenever superheat is too high.

As a result, the refrigerant’s vapour temperatures keeps rising, thus increasing the heating rate of the gas in the vapour line to the compressor through the evaporator. The saturation temperature of seawater is 212 degrees Fahrenheit. As pressure rises, a liquid’s saturation temperature rises with it.

Read more about Superheat Refrigeration

Saturated refrigerant table

Any engineer operating with the refrigerant requires a saturated refrigerant table.

It’s commonly used to calculate saturated refrigerant temperature from pressure, or vice versa, that is, pressure from saturated refrigerant temperature. These tables frequently include other relevant data like specific volume (v) and specific enthalpy (h) in addition to temperature and pressure.

Saturated refrigerant vapour

There are refrigerant conditions in addition to refrigerant states and pressure. Superheated, saturated, or subcooled are some of the conditions which enables the existence of a refrigerant.
Condition of saturation: Saturation is usually discussed in terms of temperature. The saturation temperature is the point at which a fluid transitions from vapour to liquid or vice versa. At their saturation temperatures, liquid and vapour are referred to as saturated liquid and saturated vapour, respectively.

Saturated Refrigerant
Saturation- Boiling point

Since phase shifts involving both vapour and liquid states, saturation would occur in both the condenser and evaporator. The liquid is at its peak temperature for that respected pressure, while the vapour is at its lowest temperature for the given
pressure at the time of saturation. However, at a particular pressure, both vapour and liquid are at same temperature at the saturation point.

What is evaporating temperature in refrigeration

To move heat from one medium to another, the refrigeration cycle requires a fluid known as a refrigerant. We normally think of such cycle as producing cooling, but if you’ve ever touched the rear of an air conditioner or a refrigerator, you’ll know it also creates heat.

This is particularly the case of a heat pump, that is essentially an air conditioner with the ability to switch between cooling and heating modes. The evaporator’s refrigerant “evaporates,” as the name implies. The temperature of the liquid refrigerant is somewhere between 35°F and 55°F as it enters the evaporator.

When it changes state to vapour from liquid, then it absorbs the heat without altering the temperature. Warm, humid indoor air is forced across the evaporator coil, which generates heat. This gives off most of its heat as by flowing that over the cooled coil helps the moisture to condense. A fan circulates the cooler, dryer room air back into the cooled chamber.

Saturated refrigerant condensing temperature

Subcooling is when the condenser outflow temperature is lower than the saturation temperature. There would usually be a separator, maybe a receiver, sight glass, as well as some plumbing between the evaporator intake and the condenser outlet.

All of these factors will result in a decrease in pressure. If the system did not have subcooling, the pressure loss in these things could cause the refrigerant to begin converting back into a vapour before it reaches the evaporator, reducing the evaporator’s refrigeration effect.

Also, because the refrigerant enters the evaporator is also at a reduced temperature, subcooling improves the system’s efficiency by a modest amount. Saturated condensing temperature is the temperature at which the vapour state of a refrigerant change to its liquid state.

Saturated refrigerant evaporating temperature

In this section, we are going to discuss about the saturated refrigerant evaporating temperature.

Before changing into a vapour in the evaporator, the refrigerant accumulates a lot of heat. This is known as latent heat, since it does not affect the temperature of the liquid refrigerant; instead, the heat is absorbed until vaporisation occurs.

Refrigeration is made possible by absorbing the latent heat and simultaneous rejection in the condenser coil. Saturated condensing temperature is the temperature at which the liquid state of a refrigerant change to its vapour state.


Where is saturated refrigerant vapor found?

In this section, we are going to discuss about various locations where saturated refrigerant could be found.

The evaporator, condenser, and receiver are the three sites where there is an existence of saturated refrigerant vapour. These three locations are proven to have a mixture of both refrigerant liquid and vapour. The refrigerant is said to be “saturated” when both liquid and vapour exist in it.

The temperature relationship represented by a P-T card is only effective whenever there is a combination of refrigeration vapour pressure and liquid present; otherwise it cannot be used. It enables the P-T connection in different states of a refrigerant
with a fully running refrigeration / air conditioning system.

Why does refrigerant need to change states?

Coolant gases have had the ability to absorb heat from their surroundings.

A latent heat is the heat energy that causes a cooling fluid to transform into a vapour at a given pressure for a constant saturation temperature. In other words, heat energy that induces a phase transformation of a refrigerant without changing its temperature is known as latent heat.

A form of energy, generally electricity, is being used to push the gas to transition state inside a mechanical refrigeration unit. The air around the gas is affected by this change in condition.