(Example 3)
The amount of Refrigerant
The calculation of the additional charge should take into account the
length of pipe and CF(correction Factor) value of indoor unit.
Total liquid pipe : Ø25.4 mm
Additional charge(kg)
Total liquid pipe : Ø22.2 mm
Total liquid pipe : Ø19.05 mm
Total liquid pipe : Ø15.88 mm
Total liquid pipe : Ø12.7 mm
Total liquid pipe : Ø9.52 mm
Total liquid pipe : Ø6.35 mm
Number of installed HR units
CF value of indoor unit
=
+
+
+
+
+
+
+
x 0.480(kg/m)
x 0.354(kg/m)
x 0.266(kg/m)
x 0.173(kg/m)
x 0.118(kg/m)
x 0.061(kg/m)
x 0.022(kg/m)
x 0.5(kg/m)
Amount refrigerant of Indoor units
Example) 4Way Ceiling Cassette 14.5kW -1ea, Ceiling concealed
Duct 7.3kW-2ea,
Wall Mounted 2.3kW-4ea
CF = 0.64 × 1 + 0.26 × 2 + 0.24 × 4 = 2.12 kg
CAUTION
Use only 2-series of indoor unit. Ex) ARNU/H***2
!
WARNING
• Regulation for refrigerant leakage
: the amount of refrigerant leakage should satisfy the following
equation for human safety.
If the above equation can not be satisfied, then follow the follow-
ing steps.
• Selection of air conditioning system: select one of the next
- Installation of effective opening part
- Reconfirmation of Outdoor Unit capacity and piping length
- Reduction of the amount of refrigerant
- Installation of 2 or more security device (alarm for gas leakage)
• Change Indoor Unit type
:
installation position should be over 2m from the floor (Wall
mounted type → Cassette type)
• Adoption of ventilation system
: choose ordinary ventilation system or building ventilation sys-
tem
• Limitation in piping work
: Prepare for earthquake and thermal stress
!
WARNING
• Pipe to be vacuumed : gas pipe, liquid pipe
• If the refrigerant amount is not exact, it may not operate
properly.
• If additionally bottled refrigerant amount is over 10%, condenser
burst or insufficient indoor unit performance may be caused.
!
Refrigerant charging
Ⓐ Manifold Gauge
Ⓑ Low pressure side Handle
Ⓒ High pressure side Handle
Volume of the room at which Indoor Unit of
the least capacity is installed
Total amount of refrigerant in the system
≤0.44 (kg / m
3
)
Attach the additional refrigerant table of IDU.