WARNINGS ON REFRIGERANT LEAKAGE
Outdoor unit
e.g.,
charged amount (15kg)
e.g., charged
amount (10kg)
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 10kg.
The possible amount of leaked refrigerant gas in
rooms D, E and F is 15kg.
NOTE : 2
The standards for minimum room volume are as
follows.
(1) No partition (shaded portion)
Outdoor unit
Refrigerant tubing
Indoor unit
(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.
Outdoor unit
Refrigerant tubing
Indoor unit
Very
small
room
Small
room
Medium
room
Large room
Mechanical ventilation device - Gas leak detector
NOTE 3 :
The minimum indoor floor area compared with the
amount of refrigerant is roughly as follows:
(When the ceiling is 2.7m high)
0
5
10
10
20
30
15
20
25
30
35
40
Range below the
density limit
of 0.3 kg/m³
(countermeasures
not needed)
Range above
the density limit
of 0.3 kg/m³
(countermeasures
needed)
Total amount of refrigerant
kg
Min.
indoor floor area
m²
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 R407C 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 R407C 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 (m³)
≤
Concentration limit (kg/m³)
The concentration limit of R407C which is used in
multi air conditioners is 0.3kg/m³.
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.
Important
