6
2.2
Indoor
Units
2.2.1
Placement
considerations
Placement
of
indoor
units
should
take
account
of
the
following
considerations:
Sufficient
space
for
drain
piping
and
for
access
during
servicing
and
maintenance
should
be
allowed.
To
ensure
a
good
cooling/heating
effect,
short
‐
circuit
ventilation
(where
outlet
air
returns
quickly
to
a
unit’s
air
inlet)
should
be
avoided.
To
prevent
excessive
noise
or
vibration
during
operation,
suspension
rods
or
other
weight
‐
bearing
fixings
should
typically
be
able
to
bear
twice
the
unit’s
weight.
3
Outdoor
Unit
Ducting
and
Shielding
3.1
Ducting
Requirements
Depending
on
the
height
of
adjacent
walls
relative
to
the
height
of
the
units,
ducting
may
be
required
to
ensure
proper
air
discharge.
In
the
situation
depicted
in
Figure
3
‐
3.1,
the
vertical
section
of
ducting
should
be
at
least
H
‐
h
high.
Figure
3
‐
3.1:
Top
of
unit
below
top
of
adjacent
wall
3.2
Design
Considerations
Outdoor
unit
ducting
design
should
take
account
of
the
following:
Each
duct
should
contain
no
more
than
one
bend.
Vibration
isolation
should
be
added
to
the
connection
between
the
unit
and
the
ducting
to
avoid
vibration/noise.
Installing
louvers
is
not
recommended
as
doing
so
decreases
airflow,
impacting
upon
cooling/heating
performance
and
energy
efficiency.
If
the
installation
situation
necessitates
louvers,
they
should
be
installed
at
an
angle
no
greater
than
15°
to
the
horizontal,
to
minimize
the
impact
on
airflow.
h
h
-
H
H
Before
installing
an
indoor
unit,
check
that
the
model
to
be
installed
is
as
specified
in
the
construction
drawings
and
confirm
the
correct
orientation
of
the
unit.
Ensure
that
units
are
installed
at
the
correct
height.
To
allow
smooth
condensate
drainage
and
to
ensure
unit
stability
(to
prevent
excessive
noise
or
vibration),
ensure
that
units
are
level
to
within
1°
of
the
horizontal.
If
a
unit
is
not
level
to
within
1°
of
the
horizontal,
water
leakage
or
abnormal
vibration/noise
may
occur.
Notes
for
installers
