Mitsubishi Heavy Industries SC-SL1N-E, Data Book

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 17 

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(2)  Capacity calculation method
 

(a)  Calculating the indoor unit capacity compensation

Indoor unit capacity (cooling, heating) = Indoor unit total rated capacity 

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 Capacity compensation coefficient according to temperature conditions

See item (3) (a) concerning the capacity compensation coefficient according to temperature conditions.

(b)  Calculating the outdoor unit capacity compensation

Outdoor Unit Capacity (Cooling, Heating) = Outdoor unit rated capacity (rated capacity when 100% connected)

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 Capacity compensation coefficient according to temperature conditions

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 Capacity compensation coefficient according to piping length

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 Capacity compensation coefficient according to height difference

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 Correction of heating capacity in relation to the frost on the outdoor unit 

heat exchanger

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  Capacity compensation coefficient according to indoor unit connection  

capacity

 See item (3) (a) concerning the capacity compensation coefficient according to temperature conditions.
 See item (3) (c) concerning the capacity compensation coefficient according to piping length.
 See item (3) (d) concerning the capacity compensation coefficient according to height difference. This compensation 

should be carried out only in cases where the outdoor unit is lower during cooling and higher during heating.

 See item (3) (e) correction of heating capacity in relation to the frost on the outdoor unit heat exchanger. This compen-

sation should be carried out only when calculating the heating capacity.

 See item (3) (f) concerning the capacity compensation coefficient according to indoor unit connected capacity. This 

compensation should be carried out only in cases where the indoor unit total capacity is 100% or higher.

(c)   Calculating system capacity

Compare the capacities determined in items (a) and (b) above and let the smaller value be the system capacity (cooling, 
heating).

 In cases where indoor unit total capacity (cooling, heating) > outdoor unit capacity (cooling, heating)

  System capacity (cooling, heating) = Outdoor unit capacity (cooling, heating)

 In cases where indoor unit total capacity (cooling, heating) < outdoor unit capacity (cooling, heating)

  System capacity (cooling, heating) = Indoor unit capacity (cooling, heating)

(d)  Calculating indoor unit capacity [item (c)  1 only]

Indoor unit capacity (cooling, heating) = System capacity (cooling, heating)
  

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 [(Indoor unit capacity) / (Indoor unit total capacity)]

Capacity calculation examples

Example 1

Cooling (when the indoor unit connected total capacity is less than 100%)

• Outdoor unit FDC450KXE6 ....................................................... 1 Unit

• Indoor unit FDT56KXE6A ......................................................... 7 Units

• Piping length  .............................................................................. 60 m (Equivalent length)

• Indoor, outdoor unit height difference ........................................ 15 m (Outdoor unit is lower)

• Temperature conditions  ..............................................................

Outdoor temperature: 33˚C DB

• Temperature conditions ...............................................................

Indoor temperature: 19˚C WB

<Indoor unit total cooling capacity>: Item (2) (a) calculation.

• Indoor unit rated cooling capacity: 5.6 kW

• Capacity compensation coefficient according to temperature conditions: 

   1.02 (Calculated according to Indoor 19˚C WB / Outdoor 33˚C DB);  (See page 19)

Indoor unit cooling capacity: 5.6 kW 

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 1.02 .=. 

5.7 kW

• Indoor unit total cooling capacity calculation;

indoor unit total cooling capacity: 5.7 kW 

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 7 units = 

39.9 kW

<Outdoor unit maximum cooling capacity> : Item (2) (b) calculation

• Outdoor unit rated cooling capacity: 45.0 kW

• Capacity compensation coefficient according to temperature conditions: 

   1.02 (Calculated according to Indoor 19˚C WB / Outdoor 33˚C DB);  (See page 19)

Outdoor unit cooling capacity: 45.0 kW 

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 1.02 .=. 

45.9 kW

• Capacity compensation coefficient according to piping length: 0.94 (calculated according to 60 m length);   (See page 21)

   45.9 kW 

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 0.94 = 43.1 kW