HVAC Procedure and Performance Guide

TASK : Determine layout and size of refrigerant tubing.

Training for this procedure can be found in these courses:

                         141 – Refrigeration l   and   242 – R410A Refrigerant Technology


Refrigerant tubing must be sized according to standard practices.  It must provide for required flow of liquid and gas with acceptable pressure losses.  System must make provision for return of oil to compressor and must be routed for access for installation and servicing.


  1. Identify refrigerant to be used.
  2. Determine type of refrigeration tubing to be used.
  3. Lay out routing of tubing.
  4. Select and locate necessary fittings.
  5. Make provisions for oil return.
  6. Locate refrigeration valves/sight glasses, etc., that must be included.
  7. Calculate equivalent length of tubing, fittings and valves involved.
  8. Determine size of tubing based on equivalent length of tubing, type of refrigerant and tonnage of equipment using standard practices and recommended pressure losses.
  9. Prepare sketch with appropriate notations.