Precautions In The Event Of Gas Refrigerant Leaks; Maximum Permitted Concentration Of Hfcs - Hitachi RWH-4.0VNFE Instruction Manual

REFRIGERANT AND WATER PIPING

4.2.2 Precautions in the event of gas refrigerant leaks

The installers and those responsible for drafting the specifications are obliged to comply with local safety codes and regulations in
the case of refrigerant leakage.
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C A U T I O N
• Check for refrigerant leakage in detail. If a large refrigerant leakage occurred, it would cause difficulty with breathing or harmful gases would occur
if a fire were in the room.
• If the flare nut is tightened too hard, it may crack over time and cause refrigerant leakage.
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Maximum permitted concentration of HFCs

The refrigerant R410A (charged in the outdoor unit) and the
refrigerant R134a 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
R410A
R134a
The minimum volume of a closed room where the system is
installed to avoid suffocation in case of leakage is:
System combination
4-6 HP
8 PMML0340B rev.1 - 03/2016
)
3
0.44
0.25
Minimum volume (m )
3
7.6
The formula used for the calculation of the maximum allowed
refrigerant concentration in case of refrigerant leakage is the
following:
R R: Total quantity of refrigerant charged (kg)
— = C V: Room volume (m³)
V C: Refrigerant concentration
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.