What is the right amount of subcooling?

Subcooling on systems that use a thermostatic expansion valve (TXV) should be approximately 10F to 18F. Higher subcooling indicates excess refrigerant backing up in the condenser.

What is the rule of thumb for subcooling?

The 10 degrees subcooling rule of thumb is just a rule of thumb. Many machines out there were designed to operate at 15 degrees subcooling. A low airflow or dirty evaporator can raise subcooling. A dirty condenser can lower subcooling.

How much subcooling do I need for 410a?

Most heating and cooling systems should operate at a superheat of 10F at the evaporator and between 20F to 25F at the compressor. if your HVAC system has a thermostatic expansion valve (TXV), the subcooling should be between 10F and 18F.

How much subcooling do I need for R134a?

The increase in subcooling is a result of both reduction of condenser exit temperature and increase of saturation temperature. Fig. 5 shows that the COP undergoes a maximum for both refrigerants at similar values of subcooling, i.e. about 9 K for R134a and around 11 K for R1234yf.

How do you calculate Subcool?

If we measure the temperature on the liquid line exiting the condenser coil then we know the end temperature after the refrigerant has lowered in temperature. Subtract the lower temperature measured on the liquid line from the saturated temperature and you have subcooling!

What causes low Subcool?

Low Subcooling is an indication that not enough refrigerant is contained or “packed” in the condenser. This can be due to undercharge, poor compression, or a metering device oversized or failing open (overfeeding).

What is Subcool and superheat?

Superheat occurs when that vapor is heated above its boiling point. Let’s say that refrigerant boils at 40 degrees at a low pressure in the evaporator. Condensation is when a vapor loses heat and turns into a liquid, but subcooling is when that liquid is cooled below the temperature at which it turns into a liquid.

Does adding refrigerant increase subcooling?

The difference between the measured liquid line temperature and the saturated condensing temperature is the liquid subcooling. Add refrigerant to increase subcooling. If the expansion valve goes bad, you can have a very low suction superheat when you have the proper subcooling.

What is subcooling formula?

Refrigerant liquid is considered subcooled when its temperature is lower than the saturation temperature corresponding to its pressure. The degree of subcooling equals the degrees of temperature decrease below the saturation temperature at the existing pressure. Subcooling Formula = Sat. – Liquid Line Temp.

Is there any way to calculate target subcool?

“Different manufacturers have various methods for determining target subcooling. For superheat, most manufacturers use the same charts, but this is not true of subcooling. There is no substitute for having the manufacturer’s subcooling chart. ” FREE articles on Superheat, Subcooling and A/C Troubleshooting.

How to calculate subcooling on a product chart?

The product’s pressure/temperature chart will provide you with the specific condensing temperature. Subtract the liquid line temperature from the condensing temperature. The difference is the amount of subcooling that is being performed.

How does the process of subcooling take place?

Subcooling is part of a process used to remove heat from a designated area. The process works through the use of a liquid that is made to absorb heat from the area to be cooled. This liquid is referred to as a refrigerant. Like all liquids, this refrigerant can be converted to and from a gas by altering its temperature.

How to calculate subcooling of a heating unit?

Calculate Subcooling. Measure the liquid line temperature of the device. The liquid line is the pipe that carries the refrigerant from the unit’s condensing coil to the expansion valve. To measure the temperature, strap the thermometer’s probe on the liquid line approximately six inches from the expansion valve and record the results.