Estimation Of The Refrigerant Charge - SCM CUBO2 SMART Oem Manual

OEM Manual – CUBO
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.
5
Liquid line
250 300
K65 - 3/8''(gr)
475 570
K65 - 1/2' (gr)
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).
SMART
2
6 7 8 9
350 400 450
665 760 855
Using this diagram you can calculate
refrigerant
evaporator inner volume.
You can apply also the following formula:
Y (CO charge) = 172,2222*X (Evap.Volume) +
2
750
Using this diagram you can calculate
refrigerant charge related to the pipe
diameter and lenght.
You can apply also the following formula:
(CO charge) = 50*X (Pipe Length K65 3/8")
2
Y (CO charge) = 95*X (Pipe Length K65 1/2")
2
Length [m]
10 11 12 13
500 550 600 650
950 1045 1140 1235
charge related to
14 15 16 17
700 750 800 850
1330 1425 1520 1615
the
18
900
1710
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