Sanyo MINI ECO-i XHX1252 Service Manual & Test Run Service Manual page 3

Check of Density 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 density 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 imposed
to protect the ozone layer. However, since it contains
more than air, it poses the risk of suffocation if its
density should rise excessively.
Suffocation from leakage of refrigerant is almost non-
existent. With the recent increase in the number of high
density 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 to conventional individual air conditioners.
If a single unit of the multi air 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 density 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 density may exceed the limit,
create an opening with adjacent rooms, or install
mechanical ventilation combined with a gas leak
detection device.
The density is as given below.
Total amount of refrigerant (oz)
Min. volume of the indoor unit installed room (ft.
≤ Density limit (oz/ft.
The density limit of refrigerant which is used in multi air con-
ditioners is 0.3 oz/ft. 3 (ISO 5149).
NOTE
1. If there are 2 or more refrigerating systems in a
single refrigerating device, the amount of refrigerant
should be as charged in each independent device.
For the amount of charge in this example:
e.g., charged
amount (353 oz)
Indoor unit
Room A Room B Room C Room D Room E Room F
The possible amount of leaked refrigerant gas in rooms A,
B and C is 353 oz.
The possible amount of leaked refrigerant gas in rooms D,
E and F is 529 oz.
3 )
3
)
Outdoor unit
e.g., charged
amount (529 oz)
ii
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 tubing is interconnected,
the smallest room of course becomes the object.
But when 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.
Very
small
room
Small Medium
room room
Mechanical ventilation device - Gas leak detector
3. The minimum indoor floor space compared with the
amount of refrigerant is roughly as follows (when
the ceiling is 8.8 ft. high):
3
ft.
4000
Range below
3500
the density limit of
3000
0.3 oz/ft. 3
(countermeasures
2500
not needed)
2000
1500
1000
500
0
0 200 400
Total amount of refrigerant
Outdoor unit
Refrigerant tubing
Indoor unit
Refrigerant tubing
Outdoor unit
Indoor unit
Large room
2
ft.
454
398
341
284
227
170
Range above
the density limit of
114
0.3 oz/ft. 3
57
(countermeasures
needed)
0
600 800 1000 1200
oz