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Division 1 CALCULATION OF THE ENERGY EFFICIENCY INDEX

United Kingdom

Original text. Later amendments are not shown.

For the calculation of the Energy Efficiency Index (EEI) of a household tumble drier model, the weighted Annual Energy Consumption of a household tumble drier for the standard cotton programme at full and partial load is compared to its Standard Annual Energy Consumption.

  1. (a)

    The Energy Efficiency Index (EEI) is calculated as follows and rounded to one decimal place:

    EEI = AE C SAE C × 100

    where:

    AEC

  2. weighted Annual Energy Consumption of the household tumble drier.

    3. SAEC

  3. standard Annual Energy Consumption of the household tumble drier.

  • (b)

    The Standard Annual Energy Consumption (SAEC ) is calculated in kWh/year as follows and rounded to two decimal places:

    • for all household tumble driers that are not air-vented:

      SAEC  = 140 × c 0,8

    • for air-vented household tumble driers:

      SAE C = 140 × c 0,8 − 30 × T t 60

      where:

      c

    • is the rated capacity of the household tumble drier for the standard cotton programme.

      • Tt

    • is the weighted programme time for the standard cotton programme.

  • (c)

    The weighted Annual Energy Consumption (AEC ) is calculated in kWh/year as follows and is rounded to two decimal places:

    1. (i)
      AE C = E t × 160 + P o × 525600 − T t × 160 2 + P l × 525600 − T t × 160 2 60 × 1000

      where:

      Et

    2. weighted energy consumption, in kWh and rounded to two decimal places.

      3. Po

    3. power in ‘off-mode’ for the standard cotton programme at full load, in W and rounded to two decimal places.

      4. Pl

    4. power in ‘left-on mode’ for the standard cotton programme at full load, in W and rounded to two decimal places.

      5. Tt

    5. weighted programme time, in minutes and rounded to the nearest minute.

      6. 160

    6. total number of drying cycles per year.

  • (ii)

    When the household tumble drier is equipped with a power management system, with the household tumble drier reverting automatically to ‘off-mode’ after the end of the programme, the weighted Annual Energy Consumption (AEC ) is calculated taking into consideration the effective duration of the ‘left-on mode’, according to the following formula:

    AE C = E t × 160 + P l × T l × 160 + P o × 525600 − T t × 160 − T l × 160 60 × 1000

    where:

    Tl

  • duration of the ‘left-on mode’ for the standard cotton programme at full load, in minutes and rounded to the nearest minute.

  • (d)

    The weighted programme time (Tt ) for the standard cotton programme is calculated in minutes as follows and rounded to the nearest minute:

    Tt  = (3 × Tdry  + 4 × Tdry½ )/7

    where:

    Tdry

  • programme time for the standard cotton programme at full load, in minutes and rounded to the nearest minute.

    • Tdry½

  • programme time for the standard cotton programme at partial load, in minutes and rounded to the nearest minute.

  • (e)

    The weighted energy consumption (Et ) is calculated in kWh as follows and rounded to two decimal places:

    Et  = (3 × Edry  + 4 × Edry½ )/7

    where:

    Edry

  • energy consumption of the standard cotton programme at full load, in kWh and rounded to two decimal places.

    • Edry½

  • energy consumption of the standard cotton programme at partial load, in kWh and rounded to two decimal places.

  • (f)

    For gas-fired household tumble driers, the energy consumption for the standard cotton programme at full and partial load is calculated in kWh and rounded to two decimal places, as:

    E dry = Eg dry f g + Eg dry,a E dry ½ = Eg dry ½ f g + Eg dry ½,a

    where:

    Egdry

  • gas consumption of the standard cotton programme at full load, in kWh and rounded to two decimal places.

    • Egdry½

  • gas consumption of the standard cotton programme at partial load, in kWh and rounded to two decimal places.

    • Egdry,a

  • auxiliary electricity consumption of the standard cotton programme at full load, in kWh and rounded to two decimal places.

    • Egdry½,a

  • auxiliary electricity consumption of the standard cotton programme at partial load, in kWh and rounded to two decimal places.

    • fg

  • 2,5.