37
ENGLISH
Checking procedure of limiting concentration
Check Concentration limit along following steps and take appropriate
measure depending on the situation.
Calculate amount of all the replenished refrigerant [kg (lbs)] per each
refrigerant system.
Calculate refrigerant concentration level
Calculate the volume of the room where indoor unit is installed as sin-
gle room or the smallest room.
- With partition but opened which
serve passage of air to adjoining
room
- Without partition
Concentration limit is the limit of Freon gas concentration where
immediate measures can be taken without hurting human body
when refrigerant leaks in the air. The Concentration limit shall be
described in the unit of [kg/m
3
(lbs/ft
3
)] (Freon gas weight per unit
air volume) for facilitating calculation.
Concentration limit: 0.44 kg/m
3
(0.028 lbs/ft
3
) (R410A)
Amount of additional
replenished refrigerant
Total amount of
refrigerant in the system
[kg (lbs)]
+
=
Note : In case one refrigerant facility is
divided into 2 or more refrigerant
systems and each system is
independent, amount of replenished
refrigerant of each system shall be
adopted.
Amount of pre charged
refrigerant per single unit
system
Amount of replenished
refrigerant at factory shipment
Amount of additionally
replenished refrigerant
depending on piping
length or piping
diameter by customer
Outdoor unit
Indoor unit
Outdoor unit
Indoor unit
Opening
Partition
In the case of opening
without door , or 0.15
% or more openings
(to floor space) both
above and below door)
Outdoor unit
(No.1 system)
Flow of
refrigerant
Indoor unit
Room where refrigerant leaks
(Refrigerant of the whole No.1
system flows out.)
CAUTION FOR REFRIGERANT LEAK
The installer and system specialist shall secure safety against leakage
according to local regulations or standards.
The following standards may be applicable if local regulations are not
available.
Introduction
Though the R410A refrigerant is harmless and incombustible itself ,
the room to equip the air conditioner should be large to such an extent
that the refrigerant gas will not exceed the Concentration limit even if
the refrigerant gas leaks in the room.
Concentration limit
- With partition and without opening which serve as passage of air to
adjoining room
Calculate refrigerant concentration
Total amount of refrigerant
system [kg(lbs)]
Volume of smallest room
whereindoor unit is installed
[m
3
(ft
3
)]
- In case the result of calculation exceeds the Concentration limit, perform the
same calculations by shifting to the second smallest, and the third smallest
rooms until at last the result is below the Concentration limit.
= Maximum concentration limit
[kg/m
3
(lbs/ft
3
)]
(R410A)
In case the concentration exceeds the limit
When the concentration exceeds the limit, change original plan or take
one of the countermeasures shown below:
• Countermeasure 1
Provide opening for ventilation.
Provide 0.15% or More size of opening to floor space both above
and below door, or provide opening without door.
• Countermeasure 2
Provide gas leak alarm linked with mechanical ventilator.
• Countermeasure 3
Reducing the system`s refrigerant quantity by deviding into smaller
separate system.
Outdoor unit
Indoor unit
Smallest
room
Countermeasure 2
Gas leak alarm
Mechanical ventilator
Countermeasure 1 Opening effective to ventilation
Indoor unit
Pay a special attention to the place, such as a basement, etc.
where refrigerant can stay, since refrigerant is heavier than air.
1,MFL67221438,영영 2018. 10. 4. 영영 11:30 Page 37
