Fujitsu AB* A12GATH, Design & Technical Manual

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3-3. THE EXAMPLE OF CALCULATION
„ „
EXAMPLE 1
Fig.1 Outline of the system
Outdoor
unit
Indoor
unit 1
Indoor
unit 2
Indoor
unit 3
Indoor
unit 4
Indoor
unit 5
Room 1 Room 2 Room 3 Room 4 Room 5
Pipe length, L=75m
H
ei
gh
t d
iff
er
enc
e,
H
=2
0m
Design conditions:
● Temperature
Indoor : 28°CDB / 20°CWB
Outdoor : 35°CDB
● Pipe length : 75m
● Height difference : 20m
(Outdoor unit upper side)
„ z
Selection of indoor unit
Room 1 Room 2 Room 3 Room 4 Room 5 Remark
A-1 Cooling heat load kW 6.0 6.0 6.0 2.0 1.5
A-2 Indoor unit models AUXK24 AUXK24 AUXK24 AUXB09 AUXB07
A-3 Rated capacity (TC
in
)
r
kW 7.1 7.1 7.1 2.8 2.2
See 7
A-4 Capacity at design temperature (TC
in
)
d
kW 7.7 7.7 7.7 3.0 2.4 See 7
A-5 Compensation coefficient of pipe length 0.90 See 6
A-6 Estimated capacity of indoor unit (TC
in
)
e
kW 6.9 6.9 6.9 2.7 2.2 (A-4) x (A-5)
A-7 Total rated capacity ∑(TC
in
)
r
kW 26.3
Sum of A-3
A-8 Total capacity at design temperature ∑(TC
in
)
d
kW 28.5 Sum of A-4
„ z
Preliminary selection of outdoor unit
Remark
B-1 Outdoor unit model 8HP : AJ

072LELAH
B-2 Rated capacity (TC
out
)
r
kW 22.4
See 2
B-3
Total rated capacity of indoor unit / Rated capacity of outdoor unit
∑(TC
in
)
r
/ (TC
out
)
r
% 117.4
(A-7) / (B-2)
B-4 Capacity at design temperature (TC
out
)
d
kW 25.8
See Fig.2 2)
B-5 Compensation coefficient of pipe length 0.90
See 6
B-6 Compensated capacity of outdoor unit (TC
out
)
c
kW 23.2
(B-4) x (B-5)
„ z
Decide system capacity
Remark
C-1 System capacity kW 23.2
Smaller one of
(A-8) and (B-6)
„ z
Calculate actual capacity of each indoor unit
Room 1 Room 2 Room 3 Room 4 Room 5
Remark
Actual capacity of each indoor unit kW 6.3 6.3 6.3 2.5 1.9 (C-1) x (A-3) / (A-7)
- (02 - 10) -
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