SCM CUBO2 SMART - Estimation of the refrigerant charge

OEM Manual – CUBO
2
SMART
Pag. 14
7.2.3 Estimation of the refrigerant charge
To get an estimation of total refrigerant quantity to charge in the system you should know:
 Volume of evaporator coil
 Diameter and Length of the piping
The total charge of refrigerant will be the obtained summing up the single quantity needed for the
evaporator and for fill the liquid line (refer to the below example).
Regardless from the estimation results, the minimum recommended CO2 charged is 4kg.
For estimation greater than 4kg the quantity of charged CO2 must be the estimated one.
Using this diagram you can calculate
refrigerant charge related to the
evaporator inner volume.
You can apply also the following formula:
Y (CO
2
charge) = 172,2222*X (Evap.Volume) +
750
Using this diagram you can calculate
refrigerant charge related to the pipe
diameter and lenght.
You can apply also the following formula:
(CO
2
charge) = 50*X (Pipe Length K65 3/8”)
Y (CO
2
charge) = 95*X (Pipe Length K65 1/2”)
Length [m]
Liquid line
5 6 7 8 9 10 11 12 13 14 15 16 17 18
K65 - 3/8’’(gr)
250 300 350 400 450 500 550 600 650 700 750 800 850 900
K65 - 1/2’ (gr)
475 570 665 760 855 950 1045 1140 1235 1330 1425 1520 1615 1710
Examples of estimated refrigerant charge calculation
Example 1
- Evaporator volume: 9lt.
CO2 charge calculated the first diagram is: 2300 gr.
- Piping length: 18mt for K65 3/8”.
CO2 charge calculated form the second diagram: 900 gr.
Total refrigerant charge (estimated): 2300 gr + 900 gr = 3200 gr (< 4000gr).