English
16
12. CAUTION FOR REFRIGERANT LEAKS
(Points to note in connection with refrigerant leaks)
Introduction
The installer and system specialist shall secure safety against
leakage according to local regulations or standards. The follow-
ing standards may be applicable if local regulations are not
available.
The VRV System, like other air conditioning systems, uses R410A as
refrigerant. R410A itself is an entirely safe non-toxic, non-combusti-
ble refrigerant. Nevertheless care must be taken to ensure that air
conditioning facilities are installed in a room which is sufficiently large.
This assures that the maximum concentration level of refrigerant gas
is not exceeded, in the unlikely event of major leak in the system and
this in accordance to the local applicable regulations and standards.
Maximum concentration level
The maximum charge of refrigerant and the calculation of the maxi-
mum concentration of refrigerant is directly related to the humanly
occupied space in to which it could leak.
The unit of measurement of the concentration is kg/m
3
( the weight in
kg of the refrigerant gas in 1m
3
volume of the occupied space).
Compliance to the local applicable regulations and standards for the
maximum allowable concentration level is required.
In Australia the maximum allowed concentration level of refrigerant to
a humanly space is limited to 0.35kg/m
3
for R407C and 0.44kg/m
3
for
R410A.
1.
direction of the refrigerant flow
2.
room where refrigerant leak has occurred (outflow of all
the refrigerant from the system)
Pay a special attention to the place, such as a basement, etc.
where refrigerant can stay, since refrigerant is heavier than air.
Procedure for checking maximum concentration
Check the maximum concentration level in accordance with steps 1
to 4 below and take whatever action is necessary to comply.
1.
Calculate the amount of refrigerant (kg) charged to each system
separately.
Note
•
Where a single refrigerant facility is divided into 2 entirely inde-
pendent refrigerant systems then use the amount of refrigerant
with which each separate system is charged.
2.
Calculate the smallest room volume (m
3
)
Incase like the following, calculate the volume of (A), (B) as a sin-
gle room or as the smallest room.
A.
Where there are no smaller room divisions
B.
Where there is a room division but there is an opening
between the rooms sufficiently large to permit a free flow of
air back and forth.
1.
opening between rooms
2.
partition
(Where there is an opening without a door or where there are
openings above and below the door which are each equivalent in
size to 0.15% or more of the floor area.)
3.
Calculating the refrigerant density using the results of the calcu-
lations in steps 1 and 2 above.
If the result of the above calculation exceeds the maximum con-
centration level then make similar calculations for the second then
third smallest room and so until the result falls short of the maxi-
mum concentration.
4.
Dealing with the situations where the result exceeds the maxi-
mum concentration level.
Where the installation of a facility results in a concentration in
excess of the maximum concentration level then it will be neces-
sary to revise the system. Please consult your Daikin supplier.
amount of refriger-
ant in a single unit
system (amount of
refrigerant with
which the system
is charged before
leaving the factory)
+
additional charging
amount (amount of
refrigerant added
locally in accordance
with the length or
diameter of the refrig-
erant piping)
=
total amount
of refriger-
ant (kg) in
the system
2
1
1
2
total volume of refrigerant in the
refrigerant system
≤
maximum concen-
tration level (kg/m
3
)
size (m
3
) of smallest room in which
there is an indoor unit installed
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Summary of Contents for VRV-WIII
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