APC IN ROW RD ACRD101 - Manual (Page 16)

InRow RD 10 kW Air Cooled Operation and Maintenance 8
Quantity of R410A in 1/2 in OD liquid line: (area) x (length in ft) x (density): 0.0010554 (ft 2 ) x L (ft) x
61.0 (lbm/ft
3
)
Density of liquid R410A at 40.6 ° C (105 ° F) and 260 psig: 0.98 g/cm
3
(61.0 lbm/ft
3
)
Cross sectional area for 1/2 in OD pipe is 0.0010554 ft
2
.
Liquid line charge for 1/2 in OD ACR copper tube: 0.095 kg/m (0.0644 lb/ft).
Cross sectional area for 5/8 in OD pipe is 0.001619 ft 2 .
Quantity of R410A in 5/8 in OD liquid line: (area) x (length in ft) x (density): 0.001619 (ft 2 ) x L (ft) x
61.0 (lbm/ft
3
).
Liquid line charge for 5/8 in OD ACR copper tube: 0.146 kg/m (0.099 lb/ft).
Example:
Calculate the total R410A charge for an FCB5 condenser with 25 ft of 1/2 in OD liquid piping.
Minimum outdoor design temperature is -28.9
° C (-20 ° F).
Note: Imperial units are used in this example.
Total R410A charge: 3.5 + 4.9 + 13.6 + (25*0.0644) = 23.6 lb.