High Subcooling Means

If the subcooling is too high, the system will be overcharged, reducing performance, efficiency, and ultimately damaging compressor valves and start components.

What causes high subcooling?

Excessive subcooling means the refrigerant was cooled more than normal. Possible explanations include overcharging, a restricted metering device, maladjustment (underfeeding), or faulty head pressure control during low ambient conditions.

What does high or low subcooling mean?

The Importance of Subcooling. The most basic meaning of subcooling is any temperatures below the saturation temperature. Generally, the lowest temperature a condenser can achieve, the better. In other words, the colder the refrigerant is as it flows into the evaporator coil, the more heat it will be able to absorb.

Is High subcooling overcharged?

High condenser subcooling: Because of the overcharge of refrigerant in the system, the condenser will have too much liquid backed up at its bottom, causing high subcooling. Remember, any liquid in the condenser lower than the condensing temperature is considered subcooling.

How do you reduce subcooling?

The difference between the measured liquid line temperature and the saturated condensing temperature is the liquid subcooling. Add refrigerant to increase subcooling. Recover refrigerant to reduce subcooling.

Can a dirty condenser coil cause high subcooling?

Higher Subcooled Liquid Temperatures With a dirty or blocked condenser, even the subcooled liquid temperature coming out of the condenser will be at a higher temperature. This means that the liquid temperature out of the condenser will be further from the evaporating temperature.

What causes high subcooling and normal superheat?

High superheat indicates that the amount of refrigerant in the evaporator is low or not sufficient. Subcooling indicates the amount of refrigerant that is available in the condenser. High subcooling means that there is an excessive amount of refrigerant in the condenser.

What causes high subcooling and high superheat?

If you notice a high superheat and an excessively high subcooling, this is likely a system with a liquid line restriction that is overcharged. A previous technician has likely added pounds of refrigerant into the system in an attempt to raise the low side saturated temperature to a level above freezing.

What are the symptoms of an overcharged AC system?

Common overcharged AC symptoms include the following:

• Uneven Pressure Levels. You might have trouble telling if you have varying pressure levels on your own.
• Frost Layers. ...
• No Air Flow. ...
• Unusual Noises. ...
• Weak Cooling. ...
• Increased Bills. ...
• Shutting Down Completely.

What is the purpose of subcooling?

In a refrigeration system, subcooling is used to bring the refrigerant from the condenser to the thermostatic expansion valve (VTX) in a completely liquid form. When exiting the compressor, the refrigerant is in a high temperature and high pressure state.

What happens if you have low subcooling?

Low superheat with low subcooling indicates that your evaporator is low on heat and has limited refrigerant in the condenser. To increase superheat, you can try turning the adjusting screw clockwise on the valve setting. Then, add a refrigerant to increase subcooling.

What happens if superheat is too high?

Too high of a superheat can cause the heat of compression to increase, causing the temperature at the discharge valves to increase. If the temperature increases beyond its safe operating temperature, it will cause damage to the compressor.

How do I know if my refrigeration system is overcharged?

Telltale Signs of An Overcharged Refrigeration System

1. Increased Suction Pressure. In a capillary configuration, an overcharged system will function at a higher suction pressure than designed.
2. Lower Superheat. ...
3. Greater Current Draw. ...
4. Higher Discharge Pressures. ...
5. Greater Subcooling.

How do you read subcooling?

Pipe the high side line. And we subtract that temperature from our saturation temperature. So let's

What happens if condenser is overcharged?

Excessive Condenser Heat Yet overcharging will greatly increase the temperature of the air being pushed out of your condenser unit. This should be easy to notice when holding your hand above the top of the condenser. This heat stems from the higher operating temperatures of the refrigerant itself.

What is the ideal superheat and subcooling?

“Typically” on TXV systems the Superheat will range between 8 to 28 degrees with a target of about 10 to 15 degrees. The Subcool range on TXV systems will range from about 8 to 20.

What causes high superheat?

Excessive or high superheat is an indication of insufficient refrigerant in the evaporator coil for the heat load present. This could mean that not enough refrigerant is entering the coil or this could also indicate an excessive amount of heat load on the evaporator coil. pressures will be lower than normal.

Does low airflow cause high superheat?

Dirty Evaporator Coil- A dirty air filter, evaporator coil or lack of air flow will cause superheat to measure low. Suction pressure will be low. Dirty Condenser Coil- A dirty condenser coil or lack of outdoor air flow will cause superheat to measure high.

How do I know if my condenser is clogged?

Be on the lookout for these 4 signs of a failing AC condenser:

1. Significantly reduced cooling. Is your air conditioner blowing lukewarm air even though you have cranked down the thermostat settings?
2. Refrigerant leaks. ...
3. Abnormal noises. ...
4. Electrical malfunctions.

How do you tell if your condenser is blocked?

3 Warning Signs You Have a Bad AC Condenser

1. Loud and abnormal noises coming from the unit.
2. Significantly reduced cooling capability from the unit.
3. The unit is leaking a noticeable amount of fluid past the typical amount of condensation.