Caution In Case Of Refrigerant Leakage; Maximum Permitted Concentration Of Hydrofluorocarbon (Hfc); Calculation Of Refrigerant Concentration - Hitachi UTOPIA RAS-4HVRP2E Service Manual

3 Piping work and refrigerant charge

Caution in case of refrigerant leakage

3.5 Caution in case of refrigerant leakage
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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.
• The following standards may be applicable, if local regulations are not available. International Organization for Standardiza-
tion, ISO5149 or European Standard, EN378 for R410A refrigerant gas.
• The following standards may be applicable, if local regulations are not available. International Organization for Standardiza-
tion, ISO 817 and International Electrotechnical Commission, IEC 60335-2-40:2018 and European Standard, EN 378-1:2016
for R32 refrigerant gas.

3.5.1 Maximum permitted concentration of hydrofluorocarbon (HFC)

R410A Refrigerant circuit
The R410A refrigerant gas, used in the equipment, is fireproof and non-toxic.
The maximum permissible concentration of HFC R410A gas in the air is 0.44 kg/m
Consequently, effective measures must be adopted to maintain the concentration of R410A gas in the air below 0.44 kg/
m in case of leakage.
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!
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.
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N O T E
Before the indoor unit installation, confirm that the room can keep the lower gas concentration than the limit value in order to take the
emergency countermeasures even if the gas leakage is ocurred.
R32 Refrigerant circuit
The unit installation and refrigerant piping should comply with the relevant local and national regulations for the designed
refrigerant.
Due to R32 refrigerant and depending on final refrigerant charge amount, a minimum floor area for installation must be
considered.
• If total refrigerant charge amount <1.84kg, there are no additional minimum floor area requirements.
• If total refrigerant charge amount ≥1.84kg, there are additional minimum floor area requirements to be checked.
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N O T E
In case of not achieving the minimum floor area, contact with your dealer.

3.5.2 Calculation of refrigerant concentration

R410A Refrigerant circuit
1 Calculate the total quantity of refrigerant R (kg) charged in the system. To do so, connect all the indoor units of the
rooms 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: Room volume (m ).
3
C: Refrigerant concentration (≤ 0.44 kg/m
R32 Refrigerant circuit
• The following chart and table shows the minimum floor area (A
a refrigerant system containing a certain refrigerant charge (m
height not lower than 2.2 m. (According to IEC 60335-2-40:2018 and EN 378-1:2016).
• For m <1.84 kg, IEC 60335-2-40:2018 and EN 378-1:2016 do not establish any minimum floor area restriction. In that
c
case check local regulations to ensure that no hard restrictions may apply.
63 SMGB0136 rev.0 - 07/2021
) of each room.
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) of the room in accordance with the following formula:
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C = R / V
for R410A gas).
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, according to Standard EN378-1.
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) required for the installation of an indoor unit from
min
) of R32 (A2L refrigerant), and supposing a total room
c
3