Design Technical Manual

Table Of Contents
2-5. ADDITIONAL CHARGE CALCULATION
The outdoor unit is charged refrigerant at the factory.
The additional refrigerant charge is calculated based on pipe length and outdoor unit model.
The additional refrigerant charge amount is calculated according to the following formula.
The overall refrigerant amount should not be exceed 66.1 lbs. (30kg) per outdoor unit.
Round up the calculated result to two decimal places.
CALCULATION OF ADDITIONAL CHARGE REFRIGERANT
1. Calculation of additional amount for outdoor unit
Model Ton
d
Factory charged
amount [lbs. (kg)]
a
Additional amount for
outdoor unit [lbs. (kg)]
AOUA72TLBV 6 26.01 (11.80) 6.61 (3.00)
AOUA96TLBV 8 26.01 (11.80) 6.61 (3.00)
AOUA120TLBV 10 26.01 (11.80) 14.99 (6.80)
Diameter of liquid
pipe [in. (mm)]
b
Additional amount for pipe
length [lbs./ft. (kg/m)]
ø1/4" (6.35) 0.014 (0.021)
ø3/8" (9.52) 0.039 (0.058)
ø1/2" (12.70) 0.077 (0.114)
ø5/8" (15.88) 0.120 (0.178)
ø3/4" (19.05) 0.180 (0.268)
2. Calculation of additional amount for pipe length
a : Outdoor unit 1
additional amount for
outdoor unit
lbs.
(
kg)
a : Outdoor unit 2
additional amount for
outdoor unit
lbs.
(
kg)
a : Outdoor unit 3
additional amount for
outdoor unit
lbs.
(
kg)
A= + +
=
Total
lbs.
(
kg)
Total
length
of ø5/8"
(15.88mm)
liquid pipe
a :
x 0.120
lbs./ft.
(0.178 kg /
m)
ft. (m)
lbs. (kg)
Total
length
of ø3/4"
(19.05mm)
liquid pipe
a :
x 0.180
lbs./ft.
(0.268 kg/
m)
ft. (m)
lbs. (kg)
Total
length
of ø1/2"
(12.70mm)
liquid pipe
a :
x 0.077
lbs./ft.
(0.114 kg/
m)
ft. (m)
lbs. (kg)
Total
length
of ø3/8"
(9.52mm)
liquid pipe
a :
x 0.039
lbs./ft.
(0.058 kg/
m)
ft. (m)
lbs. (kg)
Total
length
of ø1/4"
(6.35mm)
liquid pipe
a :
x 0.014
lbs./ft.
(0.021 kg/
m)
ft. (m)
lbs. (kg)
+
+
+ +B=
=
Total
lbs.
(
kg)
3. Calculation of additional charge refrigerant
C = A + B =
lbs. (kg)
Round up C to 2 decimal place.
4. Calculation of factory charged amount
d : Outdoor unit 1
factory charged amount
lbs.
(
kg)
d : Outdoor unit 2
factory charged amount
lbs.
(
kg)
d : Outdoor unit 3
factory charged amount
lbs.
(
kg)
D= + +
=
To
tal
lbs.
(
kg)
5. Total refrigerant amount check
E = C + D =
lbs.
(
kg)
Note : Check the total refrigerant amount under the following conditions.
Condition Computational formula
For 1 outdoor unit per refrigerant system : Total amount of refrigerant ≤ 77.16lbs. (35.00kg) C ≤ 77.16lbs. (35.00kg)
For 2 outdoor units per refrigerant system : Total amount of refrigerant ≤ 154.32lbs. (70.00kg) C ≤ 154.32lbs. (70.00kg)
For 3 outdoor units per refrigerant system : Total amount of refrigerant ≤ 231.49lbs. (105.00kg) C ≤ 231.49lbs. (105.00kg)
When the total refrigerant amount exceeds the limitations.
Reduce pipe length for refrigerant system.
Change the refrigerant system configuration.
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