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Efficiency calculation – MITSUBISHI ELECTRIC PE-15MYC User Manual

Page 16

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At 26˚CDB, 19˚CWB of Indoor,

Q = 21.3, SHC = 16.3, T/I = 8.3

Therefore, when air flow is 77(CMM)

Q = 21.3

(1+(1.025 - 1.0)

7/10*) 21.7(kW)

SHC = 16.3

(1+(1.044 - 1.0)

7/10*) 16.8(kW)

T/I = 8.3

(1+(1.009-1.0))

7/10*) 8.4(kW)

Note * : 7/10 = (77-70)/(80-70)

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(Step-3) Calculation of net capacity

Based on the indoor conditioned temperature (WB,DB), designed outdoor temperature (DB), and the

actual air flow obtained in Step-2, obtain the gross capacity from the gross capacity tables (pages

16~35). Then, calculate the net capacity from the formula below by using the fan motor input obtained

in Step-2.

Net capacity (kW) = Gross capacity (kW) - Fan motor input (kW)

Example: PE-8MYC

Condition:

Indoor conditioned temp. : 26˚CDB, 19˚CWB

Designed outdoor temp. : 40˚CDB

Actual air flow : 77CMM

Fan motor input : 0.6kW (See P.11)

Calculation :

The sections of the gross capacity table applicable

for the above conditions are shown right.

Therfore, the net capacity is,

Net total cooling capacity = 21.7 (kw) - 0.6(kW)

= 21.1 (kW)

Net sensible cooling capacity = 16.8 (kW) - 0.6 (kW)

= 16.2 (kW)

• Refrigerant cycle energy efficienty

(1) COP =

(2) ERR =

• System energy efficienty

(1) COP =

(2) ERR =

Notes: 1. COP : Coefficient of performance

2. EER : Energy efficiency ratio

3. Temperature condition of COP, EER (ARI Standard Ratings)

Indoor entering air temp. : 80˚FDB (=27˚CDB), 66˚FWB(=19˚CWB)

Outdoor entering air temp. : 95˚FDB (=35˚CDB)

4. Total input = Compressor input + Indoor

fan motor input + Outdoor fan motor input (page 11).

Gross total cooling capacity (kW)

Compressor input (kW)

Gross total cooling capacity (kW)

Total input (kW)

Net cooling capacity (kW)

Compressor input (kW)

Net cooling capacity (kW)

Total input (kW)

PE-8MYC-EU

AIR VOLUME

CMM

60

70

80

L/S

1,000

1,167

1,330

COOLING

CAPACITY

0.976

1.0

1.025

SHC

0.963

1.0

1.044

TOTAL INPUT

0.991

1.0

1.009

21.3

16.3

0.77

8.3

OUTDOOR DB˚C

INDOOR INDOOR

40.0

Q kW

SHC kW

SHF

T/I kW

DB˚C

WB˚C

26

19

Factor for Various Air Flow

1kW = 3412Btu/h

2. Efficiency Calculation

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