Evaporator Temp: The temperature at saturation corresponding to the evaporator pressure. Refer to a temperature-pressure chart.

Suction Vapor Temp: The suction line temperature. If there is a significant difference between the temperatures at the outlet of the evaporator and at the inlet of the compressor, use an average value. Suction line temperature cannot be less than the evaporator temperature.

Condensing Temp: The temperature at saturation corresponding to the condensing pressure. Refer to a temperature-pressure chart.

Liquid Temp: The liquid line temperature. If there is a significant difference between the temperatures at the outlet of the condenser and at the inlet of the expansion device, use an average value. Liquid line temperature cannot be greater than the condensing temperature.

Equivalent Length: Total line length including an appropriate additional length to account for pressure loss through elbows, fittings, and tees.

Vertical Height: The total vertical height of the line. Applies only to liquid line sizing. This value may be negative.

Line Capacity: The capacity the refrigerant line must handle.

For suction risers...

The app uses a 1200 ft/min (6.1 m/s) minimum refrigerant velocity when selecting the line size for a suction riser. A minimum velocity derived from Jacob's Limit is also provided. Oil entrainment up a suction riser is not solely a function of refrigerant velocity. Jacob's Limit correlates the densities of the refrigerant vapor and oil with the internal diameter of the suction line to provide a more accurate value of the minimum refrigerant velocity required for oil entrainment. This calulation uses the density of POE 32 oil for all refrigerants.

For transcritical CO2 refrigerant line sizing only...

Gas Cooler Press: The pressure in the gas cooler. This pressure must be greater than critical (1055.3 psig, 72.8 bar(g)).

Gas Cooler Outlet Temp: The temperature of the line leaving the gas cooler.

If it is desired to size liquid carrying lines used in a transcritical CO2 system, one may select subcritical CO2 from the refrigerants list and use its liquid line selection.