Precautions In The Event Of Refrigerant Leaks; Maximum Permissible Concentration Of Hydrofluorocarbon (Hfc); Calculation Of The Concentration Of Refrigerant; Countermeasures In The Event Of Refrigerant Leaks - Hitachi RCI-1.0FSN3 Service Manual

3 Piping work and
refrigerant charge

3.7 Precautions in the event of refrigerant leaks

D A N G E R
Fitters and the designers of the installations must strictly observe local and national legislation, and local codes
regarding safety requirements in the event of refrigerant leaks.

3.7.1 Maximum permissible concentration of hydrofluorocarbon (HFC)

The R410A refrigerant gas, used in the equipment, is non-flammable and non-toxic.
D A N G E R
In the event of a leak, the gas will spread around the room, displacing the air, and could therefore result in
asphyxia.
According to Standard EN378-1, the maximum permissible concentration of HFC R410A gas in the air is 0.44 kg/m
Therefore, effective measures must be adopted to maintain the concentration of R410A gas in the air below 0.44 kg/m
the event of a leak.

3.7.2 Calculation of the concentration of refrigerant

1 Calculate the total quantity of refrigerant R (kg) charged in the system; to do so, connect all the indoor units of the ro-
oms in which you wish to have air conditioning.
2 Calculate the volume V (m
3 Calculate the refrigerant concentration C (kg/m
R: total quantity of refrigerant charged (kg).
V: volume of the room (m ).
3
C: refrigerant concentration ( = 0.44 kg/m

3.7.3 Countermeasures in the event of refrigerant leaks

The room should have the following characteristics in case of a leak of refrigerant:
1 Opening without shutter to permit the circulation of fresh air in the room.
2 Opening without door measuring 0.15%, or greater, of the floor surface.
3 A fan with a capacity of at least 0.4 m
5.7 m /h) or above, connected to a gas sensor in the air conditioning system that uses refrigerant.
3
D A N G E R
Special attention should be given to areas where the refrigerant may be deposited and stay in the room, such as
basements or similar, as the gas is heavier than air.
126
SMGB0077 rev.0 - 01/2013
) of each room.
3
) of the room in accordance with the following formula:
3
R / V = C
for R410A gas).
3
/minute per ton of Japanese refrigeration (=volume moved by the compressor /
3
.
3
in
3