Installation manual

High Wall Type
Installation Manual
–31–
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.
The concentration limit of R410A which is used in multi air
conditioners is 0.019lbs/ft
3
(0.3kg/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.
For the amount of charge in this example:
The possible amount of leaked refrigerant gas in
rooms A, B and C is 22lbs (10kg).
The possible amount of leaked refrigerant gas in
rooms D, E and F is 33lbs (15kg).
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.
NOTE 3 :
The minimum indoor floor area compared with the amount
of refrigerant is roughly as follows:
(When the ceiling is 8.9ft (2.7m) high)
Total amount of refrigerant (lbs (kg))
Min. volume of the indoor unit installed room (ft
3
(m
3
))
≤ Concentration limit (lbs/ft
3
(kg/m
3
))
e.g.,
charged amount
((22lbs) 10kg)
Outdoor unit
e.g.,
charged amount
(33lbs (15kg))
Indoor unit
Room A Room B Room C Room D Room E
Room F
Important
Outdoor unit
Refrigerant piping
Indoor unit
Refrigerant piping
Outdoor
unit
Indoor
unit
Mechanical ventilation device - Gas leak detector
Very
small
room
Small
room
Medium
room
Large room
0
6
12
22 44 66
18
24
30
36
42
48
d
2
Min. indoor floor area
Total amount of refrigerant lbs
Range below the
density limit of
0.019lbs/ft
3
(0.3kg/m
3
)
(countermeasures not
needed)
Range above the density
limit of
0.019lbs/ft
3
(0.3kg/m
3
)
(countermeasures needed)
31-EN