SiEN34-705
Caution for Refrigerant Leaks
General Information
125
Step 2:
Calculate the smallest room volume (m³)
In a case like the following calculate the volume of (a), (b) as a single 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.
(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.)
C.
Where there is a gas leak detection alarm device linked to a mechanical ventilator in the
smallest room then the next smallest room will become the measurement target.
Step 3:
Calculate the refrigerant density using the results of the calculations in Step (1) and (2)
above.
If the result of the above calculation exceeds the dangerous concentration level then make
similar calculations for the second then third smallest room and so on until the result falls short
of the concentration level.
Indoor unit
Outdoor unit
Indoor unit
Outdoor unit
Opening between rooms
Partition
Smallest
room
Outdoor unit
Second
smallest
room
Indoor unit
Total volume of refrigerant
in the refrigerant system
<= Dangerous concentration (kg/m³)
Size (m
3
) of the smallest room in
which there is an indoor unit
installed
in the case of: R-407C = 0.35kg/m³, R-410A = 0.44kg/m³
