SMMS High-Wall Type
Installation Manual
– 40 –
EN
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 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 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 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 0.3 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 (10 kg)
e.g., charged amount (15 kg)
Outdoor unit
Indoor unit
Room A
Room B
Room C
Room D
Room E
Room F
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)
40-EN
High-Wall Type
