Hitachi YUTAKI S80 R410A Series Installation And Operation Manual page 35

The minimum volume of a closed room where the system is installed to avoid suffocation in case of
leakage is:
System combination
YUTAKI S80
The formula used for the calculation of the maximum allowed refrigerant concentration in cases of
refrigerant leakage is the following:
If the room volume is below the minimum value some effective measure must be taken into
account after installing to prevent suffocation is 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 of the floor area.
3 There must be a ventilator fan connected to a gas leak detector, with a ventilator capacity of
0.4 m /min or higher per Japanese refrigeration ton (= compressor displacement volume / (5.7 m
3
(R410A) or 14.4 m /h (R134a)) of the air conditioning system using the refrigerant.
3
Outdoor unit
Indoor unit

NOTE
Always take the maximum value between the R410A and R134a.
PMEN0648 rev.0 - 03/2023
4-6HP
R R: Total quantity of refrigerant charged (kg)
— = C V: Room volume (m³)
V C: Refrigerant concentration
Model
RAS-(4-6)WH(V)NPE
RWH-(4.0-6.0)(V)NF(W)E
Minimum volume (m )
3
7.6
Tonnes
R410A R134a
2.27 -
- 1.61
5
/h
3
26