VC Pro VRF 50/60Hz 
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Part 1 - General Information 
6 Selection Procedure 
6.1 Procedure 
Step 1: Establish design conditions 
 
 
 
 
 
 
Step 2: Select indoor units 
 
 
 
 
 
 
 
Step 3: Select outdoor units 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Notes: 
1.  If the indoor design temperature falls between two temperatures listed in the indoor unit's capacity table, calculate the corrected capacity by interpolation. 
If  the  indoor  unit  selection  is  to  be  based  on  total  heat  load  and  sensible  heat  load,  select  indoor  units  which  satisfy  not  only  the  total  heat  load 
requirements of each room but also the sensible heat load requirements of each room. As with total heat capacity, the sensible heat capacity of indoor 
units should be corrected for indoor temperature, interpolating where necessary. For the indoor unit capacity tables, refer to the indoor unit technical 
manuals.   
Design temperature and humidity (indoor and outdoor) 
Required heat load of each room 
System peak load   
Piping length, level differences 
Indoor unit specifications (type and quantity) 
Decide indoor unit safety factor 
Select indoor unit models ensuring that: 
Indoor unit capacity corrected for indoor air temperature WB
1
 ≥ Required heat load × Indoor unit safety factor 
Determine required total heat load on outdoor units 
Use the sum of the peak load of each room 
Provisionally  select  outdoor  unit  capacity  based  on  combination  ratio 
limitations 
Confirm that the number of indoor units connected to the outdoor units is within limitation 
Correct cooling capacities of the outdoor units for the following items: 
Outdoor  air  temperature  /  Indoor  air  temperature  WB  /  Combination  ratio  /  Piping  length,  level 
difference / Piping heat loss   
Is corrected outdoor unit capacity ≥ Required total heat load on outdoor units? 
VRF system selection is complete