Panasonic U-72MF2U9 Technical Data Manual page 20

1. Model Selection and Capacity Calculator
1-2. Procedure for Selecting Models and Calculating Capacity
Model Selection Procedure
Select the model and calculate the capacity for each refrigerant system according to the procedure shown below.
Calculation of the indoor air-conditioning load
Selection of an air conditioning system
Design of the control system
Preliminary selection of indoor and outdoor units
Check of the tubing length and elevation difference
1
Calculation of the corrected outdoor unit capacity
2
Calculation of the corrected capacity for each indoor unit
3
Recheck of the actual capacity for each indoor unit
Design of tubing
4
5
6
Calculation of additional refrigerant charge amount
7
Design of electrical wiring capacity
8
9
Calculate the maximum air-conditioning load for each room or zone.
Select the ideal air conditioning system for air conditioning of each room or zone.
Design a suitable control system for the selected air conditioning system.
Make preliminary selections that are within the allowable range for the system .
Check that the length of refrigerant tubing and the elevation difference are within the allowable
ranges....................................................................................................................................... 2-5
Capacity correction coefficient for model................................................................................ 2-12
Capacity correction coefficient for outdoor temperature conditions.................................. 2-12, 14
Capacity correction coefficient for tubing length and elevation difference........................ 2-12, 15
Heating capacity correction coefficient for frosting/defrosting.......................................... 2-12, 14
Capacity correction coefficient for indoor temperature conditions.................................... 2-13, 15
Capacity distribution ratio based on the tubing length and elevation difference............... 2-13, 15
If the capacity is inadequate, reexamine the unit combinations .
Example 1: Increasing the indoor unit capacity...................................................................... 2-17
Example 2: Increasing the outdoor unit capacity.................................................................... 2-17
Create a tubing design which minimizes the amount of additional refrigerant charge as much as
possible........................................................................................................................... 2-5 ~ 2-8
If tubing extension for additional unit is expected in the future, create the tubing design with
adequate consideration for this extension.......................................................................
Select the tubing size for the main tube (LA) up to the 1st distribution joint based on the rated
cooling capacity of the outdoor unit. Select tubing sizes after the distribution point based on the
total rated cooling capacity of the connected indoor units.
Increasing the tubing size of the wide tubes can reduce the loss of capacity caused by longer
tubing lengths. (Only the main wide tube with the largest tube diameter (main tube LA and main
tubes after the distribution point that are the same size as LA) can be changed.) In this case, it is
necessary to recalculate the actual indoor unit capacities..................................................... 2-16
Calculate the additional refrigerant charge from the diameters and lengths of the refrigerant tub-
ing. Even if the wide tubing diameter was increased, determine the additional refrigerant charge
based only on the narrow tubing size.................................................................................
Check the minimum indoor capacity (limit density) with respect to the amount of refrigerant. If th
limit density is exceeded, be sure to install ventilation equipment or take other corrective steps. 2-11
Select a wiring capacity according to the method of power supply........................................ 2-21
2 - 4
Design of 3WAY VRF SYSTEM
........
2-5 ~ 2-11
2-5 ~ 2-9
2-9, 10