9. Refrigerant and water piping
TCGB0075 rev.0 - 11/2012
101
9
Maximum permitted concentration of HFCs
The refrigerant R410A, charged in the outdoor unit, and the refrigerant R134a, charged in the indoor unit, are incombustible
and non-toxic gases. However, if leakage occurs and gas fills a room, it may cause suffocation.
The maximum permissible concentration of HFC gas according to EN378-1 is:
Refrigerant
Maximum permissible concentration (kg/m
3
)
R410A
0.44
R134a
0.25
The minimum volume of a closed room where the indoor unit is installed to avoid suffocation in case of leakage is:
Minimum volume
V > 10 m³
If the room volume is below the minimum value, some effective measure must be taken account after installing to prevent
suffocation in case of leakage.
Outdoor unit (RAS-5HVRNME-AF)
Refrigerant (R410A): 4.0 kg
Gas leak
detector
Fan m
3
/min
Height 2.5 m
Floor
10 m2
Opening: 0.06 m
2
Indoor unit
(RWH-5.0FSVNFE)
Refrigerant (R134a): 2.5 kg
Countermeasure in the event of possible refrigerant leakage
The room must have the following features to prevent suffocation in case a refrigerant leakage occurs:
1
Provide a shutterless opening which will allow fresh air to circulate into the room.
2
Provide a doorless opening of 0.15% or more size to the floor area.
3
There must be a ventilator fan connected to a gas leak detector, with a ventilator capacity of 0.4 m³/min or higher per
Japanese refrigeration ton (= compressor displacement volume / (5.7 m³/h (R410A) or 14.4 m³/h (R134a)) of the air
conditioning system using the refrigerant.
R410A
R134a
Outdoor unit model
Tonnes
Indoor unit model
Tonnes
RAS-4H(V)RNME-AF
1.35
RWH-(4.0-6.0)FS(V)NFE
1.61
RAS-(5/6)H(V)RNME-AF
1.84
N O T E
Always take the maximum value between the R410A and R134a.
4
Pay special attention to the place, such as a basement, etc., where the refrigerant can stay, since refrigerant is heavier
than air.