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Seasonal Space Heating Energy Efficiency requirements (ηs) 

‘Seasonal space heating energy efficiency”, ηs, is the ratio between the space heating demand, which is supplied by a local space heater and the annual energy consumption required to meet this demand, expressed in %.

The calculation of ηs has changed:

  • Under the old regulation (EU) 2015/1188, the consumption of electricity must be multiplied by a conversion coefficient (CC) of 2,5.
  • In the new regulation (EU) 2024/1103 CC is reduced to 1,9.

‘conversion coefficient’ (CC), (EU) 2024/1103, Annex II (29)

‘conversion coefficient’ (CC) means the default coefficient for primary energy per kWh electricity referred to in Directive 2012/27/EU of the European Parliament and of the Council; the value of the conversion coefficient is CC = 1,9.

The reduction of the Primary Energy Factor from 2.5 to 1.9 reflects the increased share of renewable energy, declining fossil fuel use, and higher efficiency in electricity generation and distribution across the EU, making electricity a cleaner and more efficient energy carrier. This update ensures more accurate accounting of primary energy consumption and supports the EU’s energy efficiency and climate goals. See more in Regulation (EU) 2023/807.

Moreover, in the regulation of 2015, ns is calculated differently for domestic and commercial LSH (LSH).

Due to the different calculation approach lower values for seasonal space heating energy efficiency requirements (ηs) for gaseous fuel LSH and liquid fuel LSH were introduced in the new regulation (EU) 2024/1103 (see examples here).