Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 793

Capacity Correction Calculations (The procedure for both cooling and heating is the same.)
Example Conditions • Unit (50 Hz)
• Piping length (Shall be common among units) .......... 60 meters (suitable length)
• Difference in height between indoor and ........... 15 meters
• Air conditions .......... Outdoor air temperature 33˚CDB
Outdoor unit performance correction
1 Total connection capacity from indoor unit ... 90 × 1 unit + 140 × 1 unit + 28 × 1 unitt + 22 × 1 unit = 280
.
= 28kW (From table above) .
2 Performance correction from indoor and outdoor temperatures
.
28 × 1.02 = 28.5kW
.
3 Performance correction from piping length and difference in height between indoor and outdoor units
. .
28.5 (0.865 - 0.03) = 23.8kW (Actual performance)
Performance correction of indoor unit
Performance correction of indoor unit = System performance ×
[Example] FDTJ90HKXE2
90
.
23.8 ×
= 7.65kW
.
280
Performance of indoor unit
FDTJ90HKXE2 ................... 7.65kW (Actual performance)
FDTJ140HKXE2 ................ 11.9kW (Actual performance)
FDTWJ28HKXE2B .......... 2.38kW (Actual performance)
FDTSJ22HKXE2B .......... 1.87kW (Actual performance)
Outdoor unit FDCJ280HKXE2B 1 unit
Indoor unit FDTJ90HKXE2 - 1 unit
FDTJ140HKXE2 - 1 unit
FDTWJ28HKXE2B - 1 unit
FDTSJ22HKXE2B - 1 unit
outdoor units
Indoor temperature 26˚CDB 19 ˚CWB
(Outdoor unit is lower)
Indoor unit capacity
Total capacity of indoor units
operating simultaneously
FDC-HKX
Corrction when
cooling?
791