The Example Of Calculation; Cooling Example - Fujitsu AOU48RLXFZ Design & Technical Manual

3-2.

THE EXAMPLE OF CALCULATION

3-2-1.

COOLING EXAMPLE

EXAMPLE 1
Outdoor unit
Indoor unit 1
Room 1
Design conditions
Design temperature
●
Indoor : 75°F DB / 63°F WB (23.9°C DB / 17.2°C WB)
Outdoor : 86°F DB (30°C DB)
Pipe length
●
Main piping length : L1=32.8ft. (10m)
Branch piping length : L2=32.8ft. (10m)
Operation mode: Cooling
●
Selection of indoor unit
A-1 Cooling heat load
A-2 Indoor unit models
A-3 Rated capacity (TC )
in r
A-4 Total rated capacity ∑(TC )
in
Connecting indoor unit
A-5
capacity (Cp)
Capacity change rate by
A-6 suction temperature of
indoor unit
Total capacity at design
A-7
temperature ∑(TC )
in d
Calculate the Maximum capacity of outdoor unit
B-1 Outdoor unit model
B-2 Rated capacity (TC )
out r
B-3 Capacity change rate by temperature conditions
B-4 Capacity change rate by indoor units connecting capacity
B-5 Compensation coefficient of pipe length
B-6 Maximum capacity of outdoor unit (TC
Decide system capacity
C-1 System capacity
Calculate actual capacity of each indoor unit
Actual capacity of each indoor
Btu
unit
Actual capacity of all indoor units is larger than cooling heat load of each room.
(When the connecting capacity for indoor unit is 100% or more)
Main Piping length, L1=32.8ft. (10m)
Branch
box
Indoor unit 2 Indoor unit 3 Indoor unit 4
Room 2 Room 3 Room 4
Room 1 Room 2 Room 3
Btu 5800 5800 5800
ASU7 ASU7 ASU7
Btu 7000 7000 7000
Btu
r
56000 / 48000 = 117% (80%≤Cp≤130%)
Btu
Btu
) Btu
out c
Room 1 Room 2 Room 3
5970 5970 5970
- (02 - 05) -
Branch Piping length, L1=32.8ft. (10m)
Branch Branch
box box
Indoor unit 5 Indoor unit 6
Room 5 Room 6
Room 4 Room 5 Room 6
5800 5800 5800
ASU7 ASU7 ASU7
7000 7000 7000
7000 x 8 = 56000
46.1 / 48.0 = 0.960
56000 x 0.960 = 53760
AOU48RLXFZ
48000
47.4 / 48.0 = 0.988
52.4 / 48.0 = 1.092
0.98 x 0.942 = 0.923
48000 x 0.988 x 1.092 x 0.923 = 47800
Btu 47800
Room 4 Room 5 Room 6 Room 7
5970 5970 5970 5970
Indoor unit 7 Indoor unit 8
Room 7 Room 8
Remark
Room 7 Room 8
5800 5800
ASU7 ASU7
7000 7000
Cooling
Sum of A-3
See Fig.1
(A-4) x (A-6)
Remark
Cooling
See Fig.1
See Fig.2
See 5-1.
(B-2) x (B-3) x (B-4) x (B-5)
Remark
Smaller one of (A-7)
and (B-6)
Room 8 Remark
5970
(A-3) x (C-1) / (A-4)
2. MODEL SELECTION