# How do you calculate subcooling and superheat?

Table of Contents

## How do you calculate subcooling and superheat?

Subtract the Liquid line Temperature from the Liquid Saturation Temperature and you get a Subcooling of 15. “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 is the formula for calculating superheat?

The total superheat calculation is as follows: Degrees compressor in temperature (50 degrees) minus saturation temperature (23 degrees) equals total superheat (27 degrees). In the above example, the total superheat was calculated to be 27 degrees.

#### What is the subcooling formula?

Calculate the subcooling as follows: subcooling = CT – T. For a refrigerant blend use the saturated liquid (bubble) temperature as the condensing temperature. Subcooling will not usually occur in the condenser unless liquid backs up in the condenser.

**How is total subcooling calculated?**

Total subcooling can be calculated by subtracting the liquid line temperature at the entrance of the metering device from the saturation temperature at that point. If there is pressure drop with the liquid travel, the concept of total subcooling is meaningless without incorporating pressure drops into the equation.

**How do you calculate superheat discharge?**

The discharge superheat can be calculated with the temperature difference.

- Discharge Superheat = Discharge line temperature at compressor – Temperature of saturated liquid.
- The total superheat is measured accurately in the system to know negligible energy loss or gain.

## How do you calculate subcooling in HVAC?

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!

### How is subcooling measured in HVAC?

Record the actual temperature of the liquid leaving the condenser with a surface temperature probe. Subtract the liquid pipe temperature (at the exit of the condenser) from the converted temperature (from the high side pressure using the pressure/temperature comparator). The difference is the amount of sub cooling.

#### How is evaporator superheat measured?

How to Measure Superheat

- Convert the evaporating pressure to temperature by using a pressure/temperature comparator.
- Subtract the temperature converted on the pressure/temperature Comparator from the actual temperature recorded at the TXV bulb.
- The difference is the actual evaporator superheat.

**How do you calculate subcooling on 410a?**

The Saturation Temperature is located on the gauge on this R410A unit by lining up the pressure with the appropriate refrigerant scale. In this example the Sat temp is 43 degrees. Subtract the two and you have 10 degrees of Superheat. The Saturation temperature for Subcooling is acquired from the high side gauge.

**Why do we calculate superheat?**

“Measuring superheat is important because it can prevent damage to the air conditioner and make it run more efficiently. Superheat is the difference between the boiling point temperature of the refrigerant in the evaporator coil and the actual temperature of the refrigerant gas as it leaves the evaporator.

## How do you calculate 410A subcooling?

Subtract the lower temperature measured on the liquid line from the saturated temperature and you have subcooling!

- 105°F Sat Temp – 93°F Actual Line Temp = 12°F of Subcooling.
- R-410A split system air conditioner.

### What is K in superheat?

The superheat value should be 4-8K (Kelvin). If the Superheat value is too high then the evaporator is not fully flooded with cold liquid refrigerant causing the evaporator to be inefficient.