Hitachi YUTAKI S80 Series Technical Catalogue page 101

9. Refrigerant and water piping

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:
The minimum volume of a closed room where the indoor unit is installed to avoid suffocation in case of leakage is:
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.
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.
Outdoor unit model
RAS-4H(V)RNME-AF
RAS-(5/6)H(V)RNME-AF
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.
101
TCGB0075 rev.0 - 11/2012
Refrigerant Maximum permissible concentration (kg/m
R410A
R134a
Minimum volume
Outdoor unit (RAS-5HVRNME-AF)
Floor
10 m2
Opening: 0.06 m Fan m /min
2 3
R410A
Tonnes
1.35
1.84
0.44
0.25
V > 10 m³
Refrigerant (R410A): 4.0 kg
Indoor unit
(RWH-5.0FSVNFE)
Refrigerant (R134a): 2.5 kg
Gas leak
detector
R134a
Indoor unit model
RWH-(4.0-6.0)FS(V)NFE
)
3
Tonnes
1.61
9