37
Piping System
3.5 Calculation of Additional Refrigerant
Table 3.1 Additional Refrigerant Charge Calculation
Although refrigerant has been charged into this unit, additional refrigerant charge is required. Determine the additional
refrigerant quantity according to the following procedure, and charge it into the system. Record the additional refrigerant
quantity to facilitate maintenance and servicing activities thereafter.
1. Calculating Method of Additional Refrigerant Charge (W lbs)
(1) Additional refrigerant charge calculation for liquid piping (W1)
Pipe Diameter Φ (in.(mm)) Total Piping Length (ft.) Refrigerant Amount for 1ft Pipe (lbs/ft) Additional Charge (lbs)
1-1/8(28.6) ft. × 0.45=
1(25.4) ft. × 0.35=
7/8(22.2) ft. × 0.24=
3/4(19.05) ft. × 0.175=
5/8(15.88) ft. × 0.114=
1/2(12.7) ft. × 0.074=
3/8(9.53) ft. × 0.038=
1/4(6.35) ft. × 0.016=
Total Additional Charge For Liquid Piping =
(2) Additional refrigerant charge calculation for indoor unit and water module (W2)
Total Capcity of Indoor Unit Used
in Heat Recovery System and NOT
Connected to SW BOX
(Cooling Only Indoor Unit) (kBtu/h)
Refrigerant Charge
(lbs/kBtu/h)
Additional Charge
(lbs)
×0.0231=
Total Other Indoor Unit and Water
Module Capcity
(kBtu/h)
Refrigerant Charge
(lbs/kBtu/h)
Additional Charge
(lbs)
× 0.0516=
Additional Charge For Indoor Unit and Water Module =
(3) Additional refrigerant charge calculation for switch box (W3)
SW BOX Model
Number of SW
BOX
Connected
Refrigerant Charge
(lbs/unit)
Additional
Charge
(lbs)
HCHM-N04XB × 0.22=
HCHM-N08XB × 0.44=
HCHM-N12XB × 0.66=
HCHM-N16XB × 0.88=
Total Additional Charge For SW BOX =
(4) Additional refrigerant charge calculation for connection ratio (W4)
Connection Ratio (Total Capacity of Indoor Unit and Water
Module / Outdoor Unit Capacity)
Refrigerant Charge (lbs)
≤ 100% 0.0lbs
(101% ~ 115%) 1.1lbs
(116% ~ 130%) 2.2lbs
(131% ~ 150%) 3.3lbs
Total additional refrigerant charge can be calculated as follows: W=W1+W2+W3+W4= lbs
To Next Page
Loading...
Need help?
General
