Data - Mitsubishi Electric City Multi PUMY-SP112VKM Technical & Service Manual

4

DATA

4-1. SELECTION OF COOLING/HEATING UNITS
<Cooling>
Outdoor Design Dry Bulb Temperature
Total Cooling Load
Room1
Indoor Design Dry Bulb Temperature
Indoor Design Wet Bulb Temperature
Cooling Load
Room2
Indoor Design Dry Bulb Temperature
Indoor Design Wet Bulb Temperature
Cooling Load
<Other>
Indoor/Outdoor Equivalent Piping Length
Capacity of indoor unit
Model Number
Model 15
for indoor unit
P•FY Series
1.7
Model Capacity
Model Number
M Series
Model 15
for indoor unit
S Series
[kW type]
P Series
1.5
Model Capacity
1. Cooling Calculation
(1) Temporary Selection of Indoor Units
Room1
PEFY-P40
Room2
PEFY-P50
(2) Total Indoor Units Capacity
P40 + P50 = P90
(3) Selection of Outdoor Unit
The SP112 outdoor unit is selected as total indoor units capacity is P90
PUMY-SP112
(4) Total Indoor Units Capacity Correction Calculation
Room1
Indoor Design Wet Bulb Temperature Correction (20ºC)
Room2
Indoor Design Wet Bulb Temperature Correction (18ºC)
Total Indoor Units Capacity (CTi)
CTi = Σ (Indoor Unit Rating × Indoor Design Temperature Correction)
= 4.5 × 1.03 + 5.6 × 0.94
= 9.9 kW
(5) Outdoor Unit Correction Calculation
Outdoor Design Dry Bulb Temperature Correction (44.7ºC)
Piping Length Correction (60 m)
Total Outdoor Unit Capacity (CTo)
CTo = Outdoor Rating × Outdoor Design Temperature Correction × Piping Length Correction
= 12.5 × 0.88 × 0.88
= 9.7 kW
(6) Determination of Maximum System Capacity
Comparison of Capacity between Total Indoor Units Capacity (CTi) and Total Outdoor Unit Capacity (CTo)
CTi = 9.9 > CTo = 9.7, thus, select CTo.
CTx = CTo = 9.7 kW
(7) Comparison with Essential Load
Against the essential load 9.0kW, the maximum system capacity is 9.7 kW: Proper outdoor units have been selected.
(8) Calculation of Maximum Indoor Unit Capacity of Each Room
CTx = CTo, thus, calculate by the calculation below
Room1
Maximum Capacity × Room1 Capacity after the Temperature Correction/(Room1,2 Total Capacity after the Temperature Correction
= 9.7 × (4.5 × 1.03)/(4.5 × 1.03 + 5.6 × 0.94)
= 4.5 kW
Room2
Maximum Capacity × Room2 Capacity after the Temperature Correction/(Room1,2 Total Capacity after the Temperature Correction)
= 9.7 × (5.6 × 0.94)/(4.5 × 1.03 + 5.6 × 0.94)
= 5.1 kW
Note: If CTx = CTi, please refer to the <Heating> section to calculate the Maximum Indoor Unit Capacity of Each Room.
Go on to the heating trial calculation since the selected units fulfill the cooling loads of Room 1, 2.
OCH668B
Design Condition
Model 20 Model 25 Model 32 Model 40
2.2 2.8 3.6 4.5
Model 18
Model 20 Model 22 Model 25 Model 35 Model 42 Model 50 Model 60 Model 71
1.8 2.0 2.2 2.5
OK: fulfills the load 4.0 kW
OK: fulfills the load 4.5 kW
44.7ºC
9.0 kW
27ºC
20ºC
4.0 kW
24ºC
18ºC
4.5 kW
60 m
Model 50 Model 63 Model 71 Model 80 Model 100
5.6 7.1 8.0 9.0
3.5 4.2 5.0 6.0
1.2
1.0
0.8
4.5 kW (Rated)
0.6
5.6 kW (Rated)
0.4
Figure 1 Indoor unit temperature correction
1.3
1.2
1.1
1.0
12.5 kW
0.9
0.8
0.7
0.6
0.5
0.4
0.3
1.03 (Refer to Figure 1)
0.2
-15
Figure 2 Outdoor unit temperature correction
0.94 (Refer to Figure 1)
1.00
0.95
0.90
0.85
0.80
0.88 (Refer to Figure 2)
0.75
0.70
0.88 (Refer to Figure 3)
0.65
0.60
0.55
0.50
Figure 3 Correction of refrigerant piping length
11
Model 125 Model 140
11.2 14.0 16.0
Model 80
Model 100
7.1 8.0 10.0
15 16 17 18 19 20 21 22
Indoor Temperature [°CW.B.]
To be used to correct indoor unit only
-10 -5 0 5 10 15 20 25 30 35 40
Outdoor Temperature [°C D.B.]
To be used to correct outdoor unit only
Total capacity of indoor unit
0 20 40 60 80
Piping equivalent length (m)
23 24
Indoor Temperature
19°C W.B
45 50
7.8
11.6
15.5
20.2