Arkansas HVACR NewsMagazine March 2025

HVACR NewsMagazine March 2025

Tech News

Determine Suction Saturated

It's important to remember that there may be instances where line set length and location may be a factor to consider. For example, a line set that travels a long distance through a very hot attic may cause the refrigerant to absorb extra heat beyond that of the evaporator coil; this could result in bad readings and appear as if the system's superheat is too high.

Temperature

The next measurement is the suction saturated temperature, which is the temperature of the refrigerant in its saturated state. Saturated means that both liquid and vapor are present at the same time and place. This saturated refrigerant is often referred to as boiling refrigerant. In this example, it is essentially the temperature of the refrigerant in roughly ⅞ of the indoor coil. One rule of thumb that has helped me is that the suction saturated temperature should be approximately 35°F lower than the inside ambient air temperature. To find the suction saturated temperature, we connect a pressure reading tool such as a digital manifold gauge or wireless probe to the suction line service port. Note: this is for cooling mode.