Calculate condenser and evaporator approach temperatures and system efficiency impact.
Saturated condensing temperature of the refrigerant. Read from the high-side pressure gauge and convert using PT chart. Higher values indicate fouling or airflow issues.
°F
For air-cooled condensers: outdoor ambient air temperature. For water-cooled: entering cooling water temperature. This is what the condenser rejects heat to.
°F
Saturated evaporating temperature of the refrigerant. Read from the low-side pressure gauge and convert using PT chart. Also called saturated suction temperature (SST).
°F
The actual temperature of the cooled space or medium. For walk-in coolers typically 35-38F, freezers -10 to 0F. The evaporator absorbs heat from this space.
°F
Design Temperature Difference (approach) for the evaporator. Typical values: medium-temp 10F TD, low-temp 8-10F TD. Lower TD means larger coil and better humidity control.
°F
Results
Condenser Approach (Split)-°F
Evaporator Approach (TD)-°F
Evaporator TD vs Design-
Efficiency Impact (per 1F condenser rise)-%
System Compression Ratio-
References: ASHRAE Refrigeration Handbook - Heat Exchangers. Typical air-cooled condenser approach: 10-20F. Evaporator TD: 8-12F for medium temp, 5-8F for low temp. Each 1F rise in condensing increases energy use approx 2%.