Sanyo ECO G SGP-EW120M2G2W, Technical Data Manual

Page: 52 / 115

System Design
5. Outdoor unit positioning requirements
D-21
b) Calculating L
U
Calculating necessary passage area S (m
2
)
(calculated on the basis that the airflow between units or rows is a standard 1.5 m/s)
Calculation of actual passage area Sa (m
2
)
• For installations on concrete pads
Sa = [(U
H
+ H) × La + 0.25La
2
] × 2(N - 1)
• For installations on catwalks
Sa = [(U
H
+ H) × La + 0.25La
2
] × 2(N - 1) + 2N × U
W
× H
U
+ 2M × U
D
× H
U
In this example, airflow to the catwalk is obstructed by a wall
In the diagram at the left, if L
W
≤
U
H
+ H
U
, airflow
to the catwalk is obstructed. Airflow from the wall
side should be assumed to be zero.
In the above formula, the second parameter is
obtained from the area of air inflow from Wall1
and Wall3 sides, and the third parameter is
obtained from the air inflow area from the Wall2
and Wall4 sides.
When L
W
> U
H
+ H
U
, obtain Sa from the above
formulae.
Calculation of Lu, the distance between rows
■
For installations on concrete pads
■
For installations on catwalks
As shown in the diagram at the left, obtain Lu from
the formula below by considering airflow from the
bottom of the unit. However, if L
W
≤
U
H
+ H
U
, Lu is
the same as for concrete pads.
Qm×N×(M-1)
S=
90
- (U
H
+H) + (U
H
+H)
2
+(S-Sa) / [2(M-1)]
Lu=
0.5
Wall
Catwalk Airflow
(S-Sa)+(U
W
× U
D
× N × (M-1)
Lu=
[U
W
× N+La × (N-1)] × (M-1)
-U
D
H
U
Catwalk
L
W
U
H
Total outdoor unit airflow (m
3
/min)
Qm=
No. of outdoor units