Mitsubishi Electric PUMY-P36NKMU4 Technical & Service Manual page 16

<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
<P•FY series>
Model Number
Model 04 Model 05 Model 06 Model 08 Model 12 Model 15 Model 18 Model 24 Model 27 Model 30 Model 36 Model 48 Model 54 Model 72
for indoor unit
Model
4.0 5.0
Capacity
<M,S,P series>
Model Capacity class
name
06 09 12
SVZ - - 12.0
SLZ-KF - 8.4 11.1 15.0
SEZ-KD - 8.1 11.5 14.1
MFZ-KJ - 9.0 12.0 15.0
MLZ-KP - 9.0 12.0
MLZ-KY 6.0 - -
MSZ-FH 6.0 9.0 12.0 15.0
MSZ-FS 6.0 9.0 12.0 15.0
MSZ-GL 6.0 9.0 12.0 14.0
MSZ-GS 6.0 9.0 12.0 14.0
MSZ-EF - 9.0 12.0 15.0
PEAD - 9.0 12.0 15.0
PLA
- - 12.0
PAA-A - - -
1. Cooling Calculation
(1) Temporary Selection of Indoor Units
Room1
PEFY-P15
Room2
PEFY-P18
(2) Total Indoor Units Capacity
P15+ P18 = P33
(3) Selection of Outdoor Unit
The P36 outdoor unit is selected as total indoor units capacity is P33
PUMY-P36NKMU4
(4) Total Indoor Units Capacity Correction Calculation
Room1
Indoor Design Wet Bulb Temperature Correction (68.0ºF)
Room2
Indoor Design Wet Bulb Temperature Correction (66.2ºF)
Total Indoor Units Capacity (CTi)
CTi = Σ (Indoor Unit Rating × Indoor Design Temperature Correction)
= 15.0 × 1.02 + 18.0 × 0.95
= 32.4 kBtu/h
(5) Outdoor Unit Correction Calculation
Outdoor Design Dry Bulb Temperature Correction (98.6ºF)
Piping Length Correction (250 ft)
Total Outdoor Unit Capacity (CTo)
CTo = Outdoor Rating × G(CTi)
× Piping Length Correction
= 36.0 × 0.98 × 0.93
= 32.8 kBtu/h
*1 G(CTi) is used only when greater than 100% indoor model size are connected in total,
refer to STANDARD CAPACITY DIAGRAM.
(6) Determination of Maximum System Capacity
Comparison of Capacity between Total Indoor Units Capacity (CTi) and Total Outdoor Unit Capacity (CTo)
CTi = 32.4 < CTo = 32.8, thus, select CTi.
CTx = CTi = 32.4 kBtu/h
OCH811A
Design Condition
6.0 8.0 12.0
15 18 24 30 36
- 18.0 24.0 30.0 36.0
- - - -
17.2 - - -
17.0 - - -
- 17.2 - - -
- - - - -
17.2 - - -
17.2 - - -
17.2 22.5 - -
18.0 22.4 - -
18.0 - - -
18.0 24.0 30.0 36.0
- 18.0 24.0 30.0 36.0
- 18.0 24.0 30.0 36.0
15.0 kBtu/h (Rated)
18.0 kBtu/h (Rated)
36.0 kBtu/h
*1
× Outdoor Design Temperature Correction
98.6ºF (37.0ºC)
30.3 kBtu/h
80.6ºF (27.0ºC)
68.0ºF (20.0ºC)
13.6 kBtu/h
75.2ºF (24.0ºC)
66.2ºF (19.0ºC)
16.7 kBtu/h
250 ft
15.0 18.0 24.0 27.0
1.02 (Refer to Figure 1)
0.95 (Refer to Figure 1)
0.98 (Refer to Figure 2)
0.93 (Refer to Figure 3)
16
30.0 36.0 48.0
1.2
1.0
0.8
0.6
0.4
59 60.8 62.6 64.4 66.2 68 69.8 71.6
15 16 17 18 19 20 21 22
Indoor Temperature
Figure 1 Indoor unit temperature correction
To be used to correct indoor unit only
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
5 14 23 32 41 50 59 68 77 86
-15 -10 -5 0 5 10 15 20 25 30
Outdoor Temperature
Figure 2 Outdoor unit temperature correction
To be used to correct outdoor unit only
Total capacity of indoor unit
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
0 50 100 150 200 250 300 350 400 450
Piping equivalent length (ft)
Figure 3 Correction of refrigerant piping length
(kBtu/h)
54.0 72.0
73.4 75.2 [°FW.B.]
23 24 [°CW.B.]
Indoor
Temperature
19.4°C (67.0°F) W.B
95 104 113 [°F D.B.]
[°C D.B.]
35 40 45
18 [kBtu/h]
27 [kBtu/h]
36 [kBtu/h]
46.8 [kBtu/h]
500 550 600