System Design - Panasonic U-72MF1U9 Technical Data Manual

2. System Design

2-1. System Example
(1) Below are the tables created using the "PAC System Diagram Software." Details of the calculations are shown in (2).
As the maximum tubing length (equivalent length) is over 295ft. in the following selection sample, the item (3) is applied due
to the main tube size up.
Selection conditions
Air condition (DB/WB)
Cooling
Max. load (BTU/h)
Air condition (DB/WB)
1
Heating
Max. load (BTU/h)
Actual tubing length
Equivalent length (with consideration for curves, etc.)
[* Equivalent length after size-up correction]
2
* Equivalent length after size-up correction is used for the calculation of actual capacity.
Preliminary selection
3
Selected model
Load (cooling/heating) (BTU/h)
Rated capacity (cooling/heating) (BTU/h)
4
(5) Corrected capacity (cooling/heating) (BTU/h)
(7) Actual capacity (cooling/heating) (BTU/h)
Total corrected capacity of indoor units (cooling/heating) = 143,323.59/161,362.40
5
Ruc = 143,323.59/147,532.93 = 0.971 < 1
Outdoor unit changes
The corrected outdoor unit capacity is less than the total corrected capacity of all indoor units in the system. As a result, the actual capacity of
each indoor unit is less than the maximum load. Therefore the outdoor unit is increased by one rank.
6
Selected model
Load (cooling/heating) (BTU/h)
7
Rated capacity (cooling/heating) (BTU/h)
(5) Corrected capacity (cooling/heating) (BTU/h)
8
(7) Actual capacity (cooling/heating) (BTU/h)
Total corrected capacity of indoor units (cooling/heating) = 143,323.59/161,362.40
Ruc = 143,323.59/168,609.06 = 0.850 < 1
Outdoor Outdoor
unit 1 unit 2
164 ft
33 ft
Elevation
difference: 33 ft
33 ft
Indoor
unit 1
Outdoor unit
91.0 / 72.0
37.0 / 35.0
296 ft
355.2 ft
[276.5 ft]
Outdoor unit
Type
96 + 72
168,000 /
189,000
147,532.93 /
146,812.33
Ruh = 161,362.40/146,812.33 = 1.099 > 1
Outdoor unit
Type
96 + 96
192,000 /
216,000
168,609.06 /
173,189.02
Ruh = 161,362.40/173,189.02 = 0.932 < 1
33 ft 66 ft
33 ft 33 ft
Indoor Indoor
unit 2 unit 3
Room 1 Room 2
(indoor unit 1) (indoor unit 2)
78.0 / 64.0 78.0 / 64.0
50,000 30,000
69.0 / 55.0 69.0 / 55.0
55,000 35,000
197 ft 230 ft
236.4 ft 276.0 ft
[157.7 ft] [197.3 ft]
Room 1 Room 2
(indoor unit 1) (indoor unit 2)
Type 54 Type 36
50,000 / 30,000 /
55,000 35,000
54,600 / 36,000 /
61,400 39,000
54,600.00 / 35,781.01 /
61,768.40 39,234.00
54,600.00 / 35,781.01 /
56,752.81 36,048.20
Room 1 Room 2
(indoor unit 1) (indoor unit 2)
Type 54 Type 36
50,000 / 30,000 /
55,000 35,000
54,600 / 36,000 /
61,400 39,000
54,600.00 / 35,781.01 /
61,768.40 39,234.00
54,600.00 / 35,781.01 /
61,400.00 39,000.00
2 - 18
Design of 3WAY VRF SYSTEM
Solenoid valve kit
Indoor
unit 4
Room 3 Room 4
(indoor unit 3) (indoor unit 4)
78.0 / 64.0 78.0 / 64.0
30,000 18,500
69.0 / 55.0 69.0 / 55.0
35,000 20,000
263 ft 296 ft
315.6 ft 355.2 ft
[236.9 ft] [276.5 ft]
Room 3 Room 4
(indoor unit 3) (indoor unit 4)
Type 36 Type 18
30,000 / 18,500 /
35,000 20,000
36,000 / 19,000 /
39,000 21,000
34,941.99 / 18,000.59 /
39,234.00 21,126.00
34,941.99 / 18,000.59 /
36,048.20 19,410.57
Room 3 Room 4
(indoor unit 3) (indoor unit 4)
Type 36 Type 18
30,000 / 18,500 /
35,000 20,000
36,000 / 19,000 /
39,000 21,000
34,941.99 / 18,000.59 /
39,234.00 21,126.00
34,941.99 / 18,000.59 /
39,000.00 21,000.00