Engineering tool

Refrigeration Pipe Sizer

Calculate the recommended suction and liquid line sizes for your refrigeration system. Enter capacity, evaporating temperature, and run length — get diameters in seconds.

Open the calculator How it works

Overview

The pipe sizer recommends suction and liquid line diameters for refrigeration systems based on the cooling capacity, evaporating temperature, refrigerant, and total run length. Correct sizing matters: undersized suction lines starve the compressor and trap oil; oversized lines drop refrigerant velocity below what is needed for oil return on vertical risers.

On the liquid line, oversizing wastes refrigerant charge and money; undersizing causes excessive pressure drop, flash gas before the expansion device, and lost capacity. The tool produces engineering-grade recommendations, but final selection still belongs to the system designer.

How it works

  1. 1Pick the refrigerant your system uses (R22, R134a, R404A/R507).
  2. 2Choose units (metric kW / m / °C, or imperial BTU/h / ft / °F).
  3. 3Enter the cooling capacity, the evaporating temperature (negative values supported, e.g. -10°C), and the total line length.
  4. 4Submit. The tool returns recommended suction and liquid line diameters.

Inputs explained

  • Refrigerant. The working fluid in the circuit. Different refrigerants have different mass-flow characteristics, so pipe sizing tables are refrigerant-specific.
  • Unit system. Metric (kW, meters, °C) or Imperial (BTU/h, feet, °F). Internally the tool converts to imperial reference tables.
  • Capacity. The evaporator load. Use the design capacity at the operating evaporating temperature.
  • Evaporating temperature. The saturation temperature inside the evaporator. Often negative for refrigeration applications (cold rooms, freezers, blast cells).
  • Total length. Equivalent length of the suction or liquid run. Add fitting equivalents to the straight pipe length for an honest answer.

Limitations & disclaimer

The tool produces recommended pipe diameters from refrigerant manufacturer reference tables. It is a starting point, not a substitute for engineering judgement, certified design, or local code. Always verify against your system pressure drop targets, oil return velocities on vertical risers, and applicable safety standards before specifying pipe.