CO2 Pipe Sizing (R744)

How do you size CO2 (R744) refrigeration pipes?

Pipes are chosen from the mass flow and the allowed velocity in each line: MT suction, LT suction and liquid. The calculator works out the mass flow from cooling capacity, evaporating temperature and superheat, picks the smallest pipe that meets the target velocity and shows the pressure drop (Darcy–Weisbach) section by section.

CO2 (R744) pipe sizing – copper →CO2 (R744) pipe sizing – steel →

Which pipes can handle CO2 system pressures?

Standard copper tube often cannot take the design pressure of a CO2 system. K65 (CuFe2P) is rated 120 bar from 3/8″ to 2-1/8″; larger sizes use steel such as P265NL or 316L stainless. The calculator warns with ⛔ when the chosen pipe type is not rated for the pressure you entered.

CO2 (R744) pipe sizing – copper →CO2 (R744) pipe sizing – steel →

What velocity should CO2 lines be sized for?

Common guide values are 8–12 m/s in suction lines and about 1 m/s in liquid lines. The calculator starts from 12 m/s and 1.2 m/s, and every value can be changed to suit the system's limits on pressure drop, noise and oil return.

CO2 (R744) pipe sizing – copper →CO2 (R744) pipe sizing – steel →

Which other tools does the site offer?

Besides CO2 in copper and steel, there are calculators for HFC/HFO and HC refrigerants (R290, R600a and others), heating and cooling water and brine, domestic water, safety valves and relief lines to EN 13136 / EN ISO 24664, GWP and CO2 equivalent under the F-gas Regulation, and conversion to another refrigerant. There are also tools for capillary tubes, pipe routing on a floor plan, electrical calculations, troubleshooting refrigeration and heat pumps, project schedules (Gantt) and a knowledge base on laws and standards.

HFC/HFO refrigerant pipe sizing →HC (A3) refrigerant pipe sizing →Pipe routing on a floor plan →Heating, cooling & brine pipe sizing →Domestic water pipe sizing →Relief valve & discharge line (EN 13136 / EN ISO 24664) →Capillary tube sizing →Cold room load →Pipe insulation →GWP, ODP & CO2e of a refrigerant charge →Refrigerant retrofit: find alternatives →Troubleshooting: refrigeration and heat pumps →Knowledge base: laws and rules →Electrical calculator →Project schedule (Gantt) →

Is it free, and do I need an account?

It is free and needs no login. Projects are saved as a file on your computer, and the printout gives a report and a flow diagram that fill an A4, A3 or A1 sheet.