ii
0001_M_I
Important
Check of Density Limit
The room in which the air conditioner is to be
installed requires a design that in the event of
refrigerant gas leaking out, its density will not
exceed a set limit.
The refrigerant R-22 which is used in the air conditioner
is safe, without the toxicity or combustibility of ammonia,
and is not restricted by laws to be imposed which protect
the ozone layer. However, since it contains more than air,
it poses the risk of suffocation if its density should rise
excessively. Suffocation from leakage of R-22 is almost
non-existent. With the recent increase in the number of
high density buildings, however, the installation of multi
air conditioner systems is on the increase because of the
need for effective use of floor space, individual control,
energy conservation by curtailing heat and carrying
power etc.
Most importantly, the multi air conditioner system is able
to replenish a large amount of refrigerant compared with
conventional individual air conditioners. If a single unit of
the multi air conditioner system is to be installed in a
small room, select a suitable model and installation
procedure so that if the refrigerant accidentally leaks out,
its density does not reach the limit (and in the event of an
emergency, measures can be made before injury can
occur).
In a room where the density may exceed the limit, create
an opening with adjacent rooms, or install mechanical
ventilation combined with a gas leak detection device.
The density is as given below.
Total amount of refrigerant (kg)
Min. volume of the indoor unit installed room (m
3
)
Density limit (kg/m
3
)
The density limit of R-22 which is used in multi air
conditioners is 0.15 kg/m
3
.
2 : The standards for minimum room
volume are as follows.
(1)
No partition (shaded portion)
(2)
When there is an effective opening with the
adjacent room for ventilation of leaking refrigerant
gas (opening without a door, or an opening 0.15%
or larger than the respective floor spaces at the top
or bottom of the door).
(3)
If an indoor unit is installed in each partitioned room
and the refrigerant tubing is interconnected, the
smallest room of course becomes the object. But
when a mechanical ventilation is installed
interlocked with a gas leakage detector in the
smallest room where the density limit is exceeded,
the volume of the next smallest room becomes the
object.
NOTE
1 : If there are 2 or more refrigerating
systems in a single refrigerating
device, the amounts of refrigerant
should be as charged in each
independent device.
NOTE
0803_M_I
e.g., charged
amount (10 kg)
Outdoor unit
Indoor unit
Room A Room B Room C Room D Room E Room F
e.g.,
charged amount (15 kg)
For the amount of charge in this example:
The possible amount of leaked refrigerant gas in
rooms A, B and C is 10 kg.
The possible amount of leaked refrigerant gas in
rooms D, E and F is 15 kg.
>
Outdoor unit
0002_M_I
Refrigerant tubing
Indoor unit
3 : The minimum indoor floor space com-
pared with the amount of refrigerant is
roughly as follows.
(When the ceiling is 2.7 m high)
NOTE
5
13.5
27.0
40.5
54.0
67.5
81.0
94.5
108
121.5
135
5
10
15
20
25
30
35
40
45
50
m
3
m
2
Total amount of refrigerant
0766_M_I
Min. indoor floor area
(when the ceiling is 2.7 m high)
Min. indoor volume
10
15
20 kg
Range below the
density limit of
0.15 kg/m
3
(Countermeasures
not needed)
Range above the
density limit of
0.15 kg/m
3
(Countermeasures
needed)
Refrigerant tubing
Outdoor unit
Very
small
room
Indoor unit
Small
room
Medium
room
Large room
Mechanical ventilation device - Gas leak detector
0003_M_I
