Toshiba MMY-SUG0801MT8P-E Installation Manual page 77

WARNINGS ON REFRIGERANT LEAKAGE
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 R32, 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 R32 is almost non-existent. However with recent increse in the number of high
concentration buildings, 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 etc.
Most importantly, the multi air conditioner system is able to hold 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 mode 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 imposed by the local regulation, create an opening with
adjacent rooms, or install mechanical ventilation or isolation, combined with a gas leak detection device, which
complies with the local regulatory requirements.
The concentration calculation method is as given below.
Total amount of refrigerant (kg)
Min. volume of the indoor unit installed room (m
Refrigerant Concentration Limit shall be in accordance with local regulations.
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.
151-EN
≤ Concentration limit (kg/m 3 )
)
3
Outdoor unit
e.g., charged amount (15 kg)
Indoor unit
Room C Room D Room E Room F
Important
NOTE 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 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.
– 76 –
Outdoor unit
Refrigerant piping
Indoor unit
Refrigerant piping Outdoor unit
Indoor unit
Very small room
Small Medium
Large room
room room
Mechanical ventilation device - Gas leak detector
EN
152-EN