Step 3: Select outdoor units
Determine the required total heat load from the indoor units to the outdoor unit based on either the sum of the peak
loads of each room or the system peak load. In this example, it is determined based on the system peak load.
Therefore, the required heat load is 10.5kW.
Provisionally select an outdoor unit using the sum of the capacity indexes (CIs) of the selected indoor units (as shown
in Table 1-5.4), ensuring that the combination ratio is between 45% and 130%. Refer to Table 1-5.5. As the sum of CIs
of the indoor units is 120, all outdoor units are potentially suitable except 8kW. Start from the smaller, which is the
10.5kW unit.
Table 1-5.4: Sum of indoor unit capacity indexes