Low -Superheat -Low -Subcooling

Low superheat and low subcooling are the indicators for your evaporator to be low on heat and have a limited refrigerator in its condenser. We will recommend you to maintain a suitable climate around your Living area in order to feel comfortable. But this notion is mostly difficult to achieve. We are here to help you in fixing this issue by telling you all the important information regarding low superheat and low subcooling through this article.

There are several causes for this phenomenon and there are several solutions as well. If you are one of those people who are facing this minor issue, you don’t need to worry any more as we are here to help you in this regard.

Low Superheat Low Subcooling; The Pertinent Reasons

There can be different reasons for low superheat including including refrigerant in the oil in excess amount in comparison to the load of heat.  In simple words, a low superheat condition occurs when there is an insufficient heat load or an excess amount of refrigerant enters into the evaporator.

There can be a number of other reasons for this condition but the most basic reasons behind this phenomena are given and explained below in detail:

AC Troubleshooting Low Superheat

  1.  Refrigerant Is In Excessive Quantity

When the refrigerant is in an excessive quantity then it starts flowing through the coils of the evaporator, and the evaporator does not absorb enough heat to vaporize the liquid refrigerants. As a result, when the evaporator fails to vaporize the liquid refrigerants we call it low superheat. Due to this refrigerant can absorb enough heat in the suction line of the evaporator and there is a chance that it can enter the compressor and damage it badly.

  1. Metering Unit Is Overfeeding

When a metering unit allows an excessive amount of refrigerants to the coils of the evaporator it will cause flooding.  If the sensing bulb of the thermal expansion valve is not insulated properly then there is a high risk that the valve can be flooded or overfed. When the entire unit is overfed, then the suction pressure and the discharge pressure may increase at high levels

  1. Reduced Air Flow From Evaporator

When we talk about some common reasons for low superheat, the one noticeable reason is the reduced airflow from the evaporator. When the airflow is reduced below the normal standards then there is not enough hot air present to vaporize the refrigerants. Due to this, the number of refrigerants reduces quickly and the liquid form of refrigerant enters the compressor of the unit and can damage the entire evaporator. Due to this both the suction pressure as well as the discharge pressure reduces at a low level. It is highly recommended to clean the dirty coils, filters, and motors to increase the airflow from the evaporator.

  1. Reduced Air Flow From Condenser

When the airflow through the condenser is extremely low, then there are high risks to increase the temperature inside the condenser and the condenser coils will stop working. You can check the high pressure by using a metering device.Then at the higher pressure refrigerants are available for the metering device. 

When the pressure is increased across the metering device more refrigerants enter through airflow, due to the more refrigerants entering the flow the discharge pressure also increases and the result is subcooling. The reason behind the low airflow through the condenser is because of poor motor bearings or some kind of obstruction in the unit. 

  1. Equipment’s Size

Also, the size of the system or unit is large as compared to a standard size, it doesn’t give enough hot heat to vaporize the liquid refrigerants. This is also counted in the reasons for low superheat. if you use the oversize unit it will increase the humidity from the normal level.

Low Superheat Normal Subcooling

This is another state where low superheat normal subcooling occurs due to the 2 pertinent reasons including plugged evaporator coils and plugged air filters. The main ingredient involved behind normal subcooling despite the lower superheat is  a liquid line receiver Which is installed in the refrigeration system. This is how the system of units works and you can indicate the problem by observing its working condition.

Frequently Asked Questions

What happens if the superheat is too low?

When the superheat reading is low or zeroes it indicates that the refrigerant did not pick up and transfer enough heat to turn it into vapors after boiling.when the Liquid refrigerant passes into the compressor it can cause typically slugging, and it can damage the valves of the compressor and internal mechanical components of the unit.

What causes low subcooling?

When we talk about low subcooling in refrigerators, the most common reason behind this is the abnormally low charge of refrigerant. When the refrigerants are low at an abnormal level it means your whole unit suffers from more than leaks, and it can restore by increasing the level of refrigerants.

How do you raise subcooling?

when you read the temperature with a thermometer, it should be lower than the saturated condensing temperature.  Liquid subcooling is the difference between the measured liquid line temperature and the saturated condensing temperature. You can increase the subcooling by adding some refrigerants. It will recover the refrigerants and increase the level of subcooling.

Does a dirty filter raise or lower superheat?

A dirty air filter or dirty evaporator coil can cause a lack of air. Lack of air pressure can cause a low level of superheating which is measurable.

Should superheat and subcooling be the same?

superheat indicates the level of refrigerants in the evaporator. while high superheat indicates the low level of refrigerants in the evaporator, and low superheat means higher level.

subcooling indicates how much refrigerants are present in the condenser.

Final Words

To Sum up the whole discussion, we can say that low superheat low subcooling may occur due to a number of reasons cited above in the article with their complete detail. We will recommend you to take care of the evaporator coil, air pressure and other important ingredients that serve in the maintenance of potential working of the unit. 

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