Fujitsu AOU48RLXFZ Design & Technical Manual page 284

[Installation precautions]
When inside When the indoor unit is installed where the
the ceiling inside of the ceiling is 86°F (30°C) RH80%
is high or greater, the dew point temperature of the
temperature outer perimeter may become higher than the
and high cabinet surface temperature and moisture will
humidity condense on the surface of the cabinet and
water drops may fall inside the room.
→Refer to Fig.A
In addition, the humidity may vary
considerably the same as when the inside of
the ceiling is close to hermetically sealed and
used as the outside air intake path.
Moist air curve
Relative humidity 80%
Dry bulb temperature 86°F (30°C)
Fig.A
When using When using an external duct to take in new
an external fresh air, etc., condensation may form on
duct the surface of the duct due to the effect of
the outside air temperature and the humidity
inside the ceiling.
When the If the cold or warm air blown out from the air
remote conditioner directly contacts the thermostat
controller section of the remote controller, the outlet
installation site temperature of the air conditioner may be
is bad
sensed and room temperature control will be
different from the room temperature and "not
cooled" or "not heated" or other trouble may
occur.
In addition, there is the possbility that the
same kind of trouble may also occur when the
remote controller is effected by direct sunlight.
Contents
Work method when reinforcing the heat insulation
of on-site piping
Slit of heat insulating
Condition which
material facing upward
requires addition of
outside heat insulation
Covered gas pipe
(heat insulation
strengthened)
Heat insulating material
(procured at the site)
Contents
- (06 - 130) -
Countermeasures (Reference)
1) Add heat insulating material
to the outside of the indoor
unit cabinet.
*Regarding the cassette type,
use of the "high humidity
correspondence kit (option)"
is recommended.
2) Strengthen the heat
insulating material of the
refrigerant piping and drain
piping also
→Refer to Fig.B
3) When the humidity inside
the ceiling changes
considerably, install a
ventilation port
Heat insulation
reinforcement material
Flare connection
(procured at the site)
Fit tightly (purpose is
Small exposed part of
Binding material
to cover the sealant)
copper pipe is desirable.
Fig.B
Countermeasures (Reference)
1) Always perform heat
insulation processing.
(Heat insulating material:
Glass wool 25mm thick or
more.)
1) Install the remote controller
where it will not be directly
exposed to the cold or hot
air.
2) Install the remote controller
where it will not be directly
exposed to sunlight or
strong lighting.
6. SYSTEM DESIGN
To indoor unit