Technical Data Manual

Design of 3WAY VRF SYSTEM
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1. Model Selecting and Capacity Calculator
<Cooling>
Elevation difference (ft)
Base capacity
change rate
*1
92 90 88 86 84 82 80 78 76
94
96
98
100
%
0 33 66 98 131 164 197 230 262 295 328 361 394 427 459 4920 33 66 98 131 164 197 230 262 295 328 361 394 427 459 492
164
131
98
66
33
0
–33
–66
–98
–131
Equivalent length (ft)
*1 Sample calculations
(System: 8 Ton, 164ft equivalent length, 49ft elevation
difference
The cooling capacity and heating capacity for this system are
found as shown below.)
●
Cooling operation
From the graph, the base capacity change rate is found to be
92.0%.
Capacity change rate is 92.0%.
(28.1kW
×
92.0% = 25.8kW)
92.0% = 88,320 BTU/h
Cooling capacity is
88,320 BTU/h (28.1 kW)
● Heating operation
From the graph, the base capacity change rate is found to be
97.2%.
Because the calculation result exceeds 97.2%, the capacity
change rate is 97.2%.
(31.6kW
× 97.2% = 30.7kW) Heating capacity is
105,000 BTU/h (30.7 kW)
Equivalent length (ft)
<Heating>
Base capacity
change rate
164
131
98
66
33
0
–33
–66
–98
–131
0 33 66 98 131 164 197 230 262 295 328 361 394 427 459 492
Elevation difference (ft)
96,000 BTU/h
×
97.2% = 105,000 BTU/h108,000 BTU/h
×
1-10. Capacity Correction Graph According to Tubing Length and Elevation Difference
Capacity change characteristics
The positive side for the elevation difference indicates that
the outdoor unit is installed at a higher position than the
indoor units. The negative side indicates the opposite.
Rated performance values
Item Cooling Heating
Type
Cooling capacity
BTU/h(kW)
Power consumption
kW
Heating capacity
BTU/h(kW)
Power consumption
kW
72 72,000(21.1) 5.30 81,000(23.7) 5.79
96 96,000(28.1) 7.75 108,000(31.6) 8.6
NOTE
TD831158-02_3WAY_VRF_SYS.indb 16TD831158-02_3WAY_VRF_SYS.indb 16 2013/06/18 11:46:352013/06/18 11:46:35