20
Air Flow (m
3
/minute)
External Static Pressure
0
50
0
5
10
15
150
10
Limit line
Limit line
HT
H
L
100
M
(mmAq)
(Pa)
30
40
Air Flow (m
3
/minute)
External Static Pressure
0
50
0
5
10
15
150
20
Limit line
Limit line
L
100
M
H
(mmAq)
(Pa)
HT
30
Air Flow (m
3
/minute)
External Static Pressure
0
50
0
5
10
15
150
20
Limit line
HT
L
100
M
H
Limit line
(mmAq)
(Pa)
436 Type
448 Type
425 Type
16
Air bleeder
25 cm or less
Upward gradient
Support
pieces
CAUTION
• Do not install an air bleeder, as this may cause water to spray from the drain pipe outlet. (Fig. 3-39)
• If it is necessary to increase the height of the drain pipe, the section directly after the connection port can be raised
a maximum of 25 cm. Do not raise it any higher than 25 cm, as this could reasult in water leaks. (Fig. 3-40)
• Do not install the pipe with an upward gradient from the connection port. This will cause the drain water to flow
backward and leak when unit is not operating. (Fig. 3-41)
• Do not apply force to the piping on the unit side when connecting the drain pipe. The pipe should not be allowed to
hang unsupported from its connection to the unit.
Fasten the pipe to a wall, frame or other support as close to the unit as possible. (Fig. 3-42)
Fig. 3-39
Fig. 3-40
Fig. 3-41
Fig. 3-42
3-12. Increasing the Fan Speed
If external static pressure is too great (due to long extension
of ducts, for example), the air flow volume may drop too low
at each air outlet. This problem is solved by increasing the fan
speed using the following procedure:
(1)
Remove 4 screws on the electrical component box
and remove the cover plate.
(2)
Disconnect the fan motor sockets in the box.
(3)
Take out the booster cable (with sockets at both ends)
clamped in the box.
(4)
Securely connect the booster cable sockets between
the disconnected fan motor sockets in step 2 as shown
in the Fig. 3-43.
(5)
Place the cable neatly in the box and reinstall the cover
plate.
Electrical component box
Booster cable
Booster cable
Fan
motor
(Booster cable installed)
(At shipment)
Fan motor socket
Fig. 3-43
Fig. 3-44
NOTE
HT : Using the
booster
cable
H
: At shipment
INDOOR FAN PERFORMANCE
EG
■
HOW TO READ THE DIAGRAM
The vertical axis is the external static pressure (mmAq) while the horizontal axis represents the AIR FLOW (m3/min.). The
characteristic curves for “HT”, “H”, “Med”, and “Low” fan speed control are shown. The nameplate values shown are based on the
“H” air flow. In case of model 425 type, the air flow is 18 m3/min., while the external static pressure is 49 Pa at “H” position. If external
static pressure is too great (due to long extension of duct, for example), the air flow volume may drop too low at each air outlet.
This problem may be solved by increasing the fan speed as explained above.
