Installation Manual
Toshiba 1112750201 (EN)
Check of Concentration 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
concentration will not exceed a set limit.
The refrigerant R410A 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 concentration should rise
excessively. Suffocation from leakage of R410A is
almost non-existent. With the recent increase in the
number of high concentration buildings, however,
the installation of multi air conditioner systems is on
the increase because of the need for effective use of
fl oor 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 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 concentration
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 concentration may exceed the
limit, create an opening with adjacent rooms, or install
mechanical ventilation combined with a gas leak
detection device.
The concentration is as given below.
Total amount of refrigerant (kg)
Min. volume of the indoor unit installed room (m
3
)
≤
Concentration limit (kg/m
3
)
The concentration limit of R410A which is used in
multi air conditioners is 0.44 kg/m
3
.
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.
e.g., charged amount (15 kg)
Outdoor unit
e.g., charged amount
(10 kg)
Room A Room B Room C Room D Room E Room F
Indoor unit
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.
Important
0
5
10
15
20
25
30
35
40
m²
10
20
30
NOTE 2 :
The standards for minimum room volume are
as follows.
(1) No partition (shaded portion)
NOTE 3 :
The minimum indoor fl oor area compared with the
amount of refrigerant is roughly as follows: (When the
ceiling is 2.7 m high)
(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 fl oor spaces at the
top or bottom of the door).
(3) If an indoor unit is installed in each partitioned
room and the refrigerant piping 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.
Outdoor unit
Refrigerant piping
Indoor unit
Indoor unit
Outdoor unit
Refrigerant piping
Mechanical ventilation device - Gas leak detector
Very
small
room
Small
room
Medium
room
Large room
Min. indoor fl
oor area
Total amount of refrigerant
kg
Range below the
density limit of
0.44 kg/m
3
(countermeasures
not needed)
Range above the
density limit of
0.44 kg/m
3
(countermeasures
needed)
WARNINGS ON REFRIGERANT LEAKAGE
Summary of Contents for MML-AP0074NH-E
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