Panasonic U-72MF2U9 Technical Data Manual

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Design of 3WAY VRF SYSTEM2 - 41234567891. Model Selection and Capacity CalculatorSelect the model and calculate the capacity for each refrigerant system according to the procedure shown below.Calculation of the indoor air-conditioning loadCalculate the maximum air-conditioning load for each room or zone.Selection of an air conditioning systemSelect the ideal air conditioning system for air conditioning of each room or zone.Design of the control systemDesign a suitable control system for the selected air conditioning system.Preliminary selection of indoor and outdoor unitsMake preliminary selections that are within the allowable range for the system ......... 2-5 ~ 2-11Check of the tubing length and elevation differenceCheck that the length of refrigerant tubing and the elevation difference are within the allowableranges....................................................................................................................................... 2-5Calculation of the corrected outdoor unit capacityCapacity correction coefficient for model................................................................................ 2-12Capacity correction coefficient for outdoor temperature conditions.................................. 2-12, 14Capacity correction coefficient for tubing length and elevation difference........................ 2-12, 15Heating capacity correction coefficient for frosting/defrosting.......................................... 2-12, 14Calculation of the corrected capacity for each indoor unitCapacity correction coefficient for indoor temperature conditions.................................... 2-13, 15Capacity distribution ratio based on the tubing length and elevation difference............... 2-13, 152-9, 10Recheck of the actual capacity for each indoor unitIf the capacity is inadequate, reexamine the unit combinations .Example 1: Increasing the indoor unit capacity...................................................................... 2-17Example 2: Increasing the outdoor unit capacity.................................................................... 2-17Design of tubingCreate a tubing design which minimizes the amount of additional refrigerant charge as much aspossible........................................................................................................................... 2-5 ~ 2-82-5 ~ 2-9If tubing extension for additional unit is expected in the future, create the tubing design withadequate consideration for this extension.......................................................................Select the tubing size for the main tube (LA) up to the 1st distribution joint based on the ratedcooling capacity of the outdoor unit. Select tubing sizes after the distribution point based on thetotal rated cooling capacity of the connected indoor units.Increasing the tubing size of the wide tubes can reduce the loss of capacity caused by longertubing lengths. (Only the main wide tube with the largest tube diameter (main tube LA and maintubes after the distribution point that are the same size as LA) can be changed.) In this case, it isnecessary to recalculate the actual indoor unit capacities..................................................... 2-16Calculation of additional refrigerant charge amountCalculate 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 chargebased only on the narrow tubing size.................................................................................Check the minimum indoor capacity (limit density) with respect to the amount of refrigerant. If thlimit density is exceeded, be sure to install ventilation equipment or take other corrective steps. 2-11Design of electrical wiring capacitySelect a wiring capacity according to the method of power supply........................................ 2-211-2. Procedure for Selecting Models and Calculating CapacityModel Selection Procedureྥྥ