Panasonic WU-144MF1U9E Technical and Service Data - Page 25

1. Model Selecting and Capacity Calculator Design of 3WAY VRF SYSTEM 1-8. Calculation of Actual Capacity of Indoor Unit Calculating the actual capacity of each indoor unit Because the capacity of a multi air-conditioner changes according to the temperature conditions, tubing length, elevation difference and other factors, select the correct model after taking into account the various correction values. When selecting The model, calculate the corrected capacities of the outdoor unit and each indoor unit. Use the corrected outdoor unit capacity and the total corrected capacity of all the indoor units to calculate the actual final capacity of each indoor unit. 1. Outdoor unit capacity correction coefficient Find the outdoor unit capacity correction coefficient for the following items. (1) Capacity correction for the outdoor unit model The capacity correction coefficient is 1.00. (2) Capacity correction for the outdoor unit temperature conditions Cooling: From the graph of capacity characteristics on page 2-13 ( Graph of Outdoor Unit Capacity Characteristics), use the outdoor temperature to find the capacity correction coefficient. Heating: From the graph of capacity characteristics on page 2-15, use the outdoor temperature to find the capacity correction coefficient. * Indoor air intake temperature should be set to 68 °FDB. (3) Capacity correction for the outdoor unit tubing length and elevation difference From the graph of capacity change characteristics on page 2-14, use the tubing length and elevation difference to find the capacity correction coefficient. The outdoor unit correction coefficient is the value which corresponds to the most demanding indoor unit. (4) Capacity correction for outdoor unit frosting/defrosting during heating 1 From the table on page 2-13, find the capacity correction coefficient. 2. Indoor unit capacity correction coefficients Find the indoor unit capacity correction coefficient for the following items. (2) Capacity correction for the indoor unit temperature conditions 2 From the graph of capacity characteristics on page 2-14 ( Graph of Indoor Unit Capacity Characteristics), use the indoor temperature to find the capacity correction coefficient. (3) Capacity distribution ratio based on the indoor unit tubing length and elevation difference First, in the same way as for the outdoor unit, use the tubing length and elevation difference for each indoor unit to find the correction coefficient from the graph of capacity change characteristics on page 2-14. Then divide the result by the outdoor 3 unit correction coefficient to find the capacity distribution ratio for each indoor unit. Capacity distribution ratio for each indoor unit (3) = Correction coefficient for that indoor unit / Correction coefficient for the outdoor unit 3. Calculating the corrected capacities for the outdoor unit and each indoor unit The corrected capacities for the outdoor unit and each indoor unit are calculated form the formula below. 4 Outdoor unit corrected cooling capacity (5) = Outdoor unit rated cooling capacity × Correction coefficient for model ((1) Page 2-11) × Correction coefficient for outdoor temperature conditions ((2) Page 2-13) × Correction coefficient for tubing length and elevation difference 5 ((3) Page 2-14) * However, if the outdoor unit corrected cooling capacity [5] is greater than 100%, then the outdoor unit corrected cooling capacity [5] is considered to be 100%. Corrected cooling capacity of each indoor unit (5) = Rated cooling capacity for that indoor unit × Correction coefficient for indoor temperature conditions at that indoor unit ((2) Page 2-14) × Distribution ratio based on tubing length and elevation difference at that indoor unit ((3) Page 2-14) 6 However, the corrected cooling capacity of each indoor unit is found as shown below. If (2) < 100% and (2) × (3) > 100%: Corrected cooling capacity for that indoor unit [5] = Rated cooling capacity for that indoor unit If (2) >100%: Corrected cooling capacity for that indoor unit (5) = Rated cooling capacity for that indoor unit × (2) 7 8 2 - 11