Mitsubishi Electric CITY MULTI PUMY-P200YKM3, Руководство по обслуживанию

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OCH791 _13
5-1-2. Heating
Design condition
Outdoor wet bulb temperature 2°C
Total heating load 20.4 kW
Room 1 Indoor dry bulb temperature 21°C
Heating load 9.5 kW
Room 2 Indoor dry bulb temperature 23°C
Heating load 10.9 kW
Other Indoor/Outdoor piping equivalent length 40 m
Capacity of indoor unit
P·FY series Model class of indoor unit 10 15
— 20 — 25 32 — 40 — 50 — 63 71 80 100 125 140 200
Model Capacity (kW)
1.4 1.9 — 2.5 — 3.2 4.0 — 5.0 — 6.3 — 8.0 9.0 10.0 12.5 16.0 18.0 25.0
M series
S series
P series
Model class of indoor unit —
15 — 20 22 25 — 35 — 42 50 60 — 71 — 100 — — —
Model Capacity (kW)
— 1.7 — 2.3 2.5 2.9 — 4.0 — 4.8 5.7 6.9 — 8.1 — 11.2 — — —
■ Heating calculation
• Tentative selection of indoor units
Room1: PEFY-P80 10.0 kW (Rated)
Room2: PEFY-P100 12.5 kW (Rated)
In this case, the total capacity is 22.5. (10.0 + 12.5 = 22.5)
• Tentative selection of outdoor unit
Proper outdoor unit in this case is P200 as the total capacity of the indoor units is 22.5.
PUMY-P200 25.0 kW
• Calculation for the corrected capacity of the total indoor units (CTi)
Correction factor for indoor temperature: Room 1 (21°C) 0.96 (Refer to Figure 3.)
Room 2 (23°C) 0.88 (Refer to Figure 3.)
CTi = Σ (Rated capacity of indoor unit × Correction factor for indoor temperature)
= 10.0 × 0.96 + 12.5 × 0.88
= 20.6 kW
• Calculation for the corrected capacity of the outdoor unit (CTo)
Correction factor for outdoor temperature (2°C WB) 1.00 (Refer to Figure 4.)
Correction factor for piping length (40 m) 0.98 (Refer to "Correcting Capacity".)
Correction factor for defrosting 0.89 (Refer to Table 1.)
CTo = Rated capacity of outdoor unit × Correction factor for outdoor temperature × Correction factor for piping length ×
Correction factor for defrosting
= 25.0 × 1.00 × 0.98 × 0.89
= 21.8 kW
Table 1 Table of correction factor for frosting and defrosting
Outdoor inlet air temp. (°C) 6 4 2 0 -2 -4 -6 -8 -10 -15 -20
Correction factor 1.00 0.98 0.89 0.88 0.89 0.90 0.95 0.95 0.95 0.95 0.95
• Determination of maximum system capacity (CTx)
Comparison between CTi and CTo:
CTi = 20.6 < CTo = 21.8, thus, select CTi.
CTx = CTi = 20.6 kW
• Comparison with essential load
Against the essential load 20.4 kW, the maximum system capacity is 20.6 kW: Proper indoor units have been select-
ed.
• Calculation for the maximum indoor unit capacity of each room
When CTx = CTi, use the calculation formula below.
Room1: Rated capacity of Indoor unit × Correction factor for indoor temperature
= 10.0 × 0.96
= 9.6 kW
The capacity is enough for the heating load of Room 1 (9.5 kW): A proper indoor unit is selected.
Room2: Rated capacity of indoor unit × Corrected capacity for the indoor design temperature
= 12.5 × 0.88
= 11.0 kW
The capacity is enough for the heating load of Room 2 (10.9 kW): A proper indoor unit is selected.
Note:
• If CTx = CTo, refer to the calculation formula in "Cooling" to calculate the maximum indoor unit capacity of each
room.
• The selection of units is completed when proper units are selected.