Refrigerant Line Charge Calculator

The Refrigerant Line Charge Calculator helps HVAC contractors accurately calculate the amount of refrigerant needed to charge the liquid and suction lines in a split cooling system. This calculation ensures proper system function and efficiency by accounting for the additional refrigerant required based on the length and diameter of the refrigerant lines.

How the Calculator Works:

1. Refrigerant Type Selection:
   • The user chooses between common refrigerants, such as R-410A or R-22.
2. Line Length Input:
   • The user inputs the length of the refrigerant lines, which can be in inches, feet, yards, centimeters, or meters.
3. Piping Diameter Selection (OD):
   • The user selects the outer diameter (OD) of both the liquid line and the suction line. Different line sizes will require different amounts of refrigerant.

How the Results Are Calculated:

• The calculator determines the refrigerant charge needed per foot of pipe based on predefined values from a reference table.
• The total charge is calculated by multiplying the length of each line (liquid and suction) by the respective charge per foot, depending on the selected refrigerant type and pipe diameter.

Results:

The results show the total amount of refrigerant needed for the lines in ounces (oz), allowing HVAC contractors to accurately charge the system and avoid over- or under-charging.

Reference Table for Calculation:

The following tables display the charge required per foot of piping for two types of refrigerants: R-410A and R-22. The charge values assume a suction temperature of 40°F and a liquid temperature of 105°F.

R-410A Refrigerant

Liquid Line Size (OD)	Charge per Foot	Suction Line Size (OD)	Charge per Foot
1/4″	0.19 oz/ft	1/2″	0.04 oz/ft
5/16″	0.33 oz/ft	5/8″	0.06 oz/ft
3/8″	0.51 oz/ft	3/4″	0.09 oz/ft
1/2″	1.01 oz/ft	7/8″	0.12 oz/ft
5/8″	1.64 oz/ft	1-1/8″	0.2 oz/ft
3/4″	2.46 oz/ft	1-3/8″	0.31 oz/ft
7/8″	3.27 oz/ft	1-5/8″	0.43 oz/ft
1-1/8″	5.58 oz/ft	2-1/8″	0.76 oz/ft
2-5/8″	1.17 oz/ft	N/A	N/A

R-22 Refrigerant

Liquid Line Size (OD)	Charge per Foot	Suction Line Size (OD)	Charge per Foot
1/4″	0.23 oz/ft	1/2″	0.02 oz/ft
5/16″	0.4 oz/ft	5/8″	0.04 oz/ft
3/8″	0.62 oz/ft	3/4″	0.06 oz/ft
1/2″	1.12 oz/ft	7/8″	0.08 oz/ft
5/8″	1.81 oz/ft	1-1/8″	0.14 oz/ft
3/4″	2.688 oz/ft	1-3/8″	0.21 oz/ft
7/8″	3.78 oz/ft	1-5/8″	0.3 oz/ft
1-1/8″	6.46 oz/ft	2-1/8″	0.53 oz/ft
2-5/8″	0.81 oz/ft	N/A	N/A

The calculator's output ensures that HVAC contractors apply the right amount of refrigerant based on line specifications, preventing system malfunctions due to incorrect refrigerant levels.