Toshiba MMW-AP0271LQ-E Installation Manual page 32

Warnings on Refrigerant Leakage
Check of Concentration Limit
The room in which the air conditioner (including hot water module) 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 (including hot water module) 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 (including hot water module) 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 (including hot water module) is able to replenish a large amount
of refrigerant compared with conventional individual air conditioners. If a single unit of the multi conditioner system
(including hot water module) 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 (including hot water module)
installed room (m
The concentration limit of R410A which is used in multi air conditioners (including hot water module) is 0.3 kg/m
▼ 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 (10 kg)
Room A Room B
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.
▼ NOTE 2
The standards for minimum room volume are as follows.
1) No partition (shaded portion)
61-EN
3
≤ Concentration limit (kg/m )
3
)
Outdoor unit
e.g., charged amount (15 kg)
Indoor unit
or
hot water module
Room C Room D Room E Room F
– 31 –
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 (including hot water module) 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.
3 .
Very small room
▼ NOTE 3
The minimum indoor floor area compared with the amount of refrigerant is roughly as follows:
(When the ceiling is 2.7 m high)
m
Important
Outdoor unit
Refrigerant piping
Indoor unit
or
hot water module
Refrigerant piping
Outdoor unit
Indoor unit
or
hot water module
Medium
Small
Large room
room room
Mechanical ventilation device - Gas leak detector
40
Range below the
2
35
density limit of
3
0.3 kg/m
30
(countermeasures
not needed)
25
20
Range above the
3
density limit of 0.3 kg/m
15
(countermeasures
needed)
10
5
0
10 20 30
Total amount of refrigerant kg
62-EN