{
  "url": "https://openlegislation.uk/eu-regulation-2014-1253/annex-VIII",
  "json_url": "https://openlegislation.uk/eu-regulation-2014-1253/annex-VIII.json",
  "legislation": "eur/2014/1253",
  "legislation_title": "Commission Regulation (EU) No 1253/2014 of 7 July 2014 implementing Directive 2009/125/EC of the European Parliament and of the Council with regard to ecodesign requirements for ventilation units (Text with EEA relevance)",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2014-1253",
  "path": "annex/VIII",
  "kind": "annex",
  "number": "VIII",
  "heading": "Calculation of the specific energy consumption requirement",
  "text": "The specific energy consumption SEC is calculated with the following equation:\nSEC = t a × pef × q net × MISC × CTRL x × SPI − t h × ΔΤ h × η – 1 h × c air × q ref − q net × CTRL × MISC × 1 − η t + Q defr\nwhere:\nSEC is Specific Energy Consumption for ventilation per m2 heated floor area of a dwelling or building [kWh/(m2.a)];\nta is annual operating hours [h/a];\npef is primary energy factor for electric power generation and distribution [-];\nqnet is net ventilation rate demand per m2 heated floor area [m3/h.m2];\nMISC is an aggregated general typology factor, incorporating factors for ventilation effectiveness, duct leakage and extra infiltration [-];\nCTRL is ventilation control factor [-];\nx is an exponent that takes into account non-linearity between thermal energy and electricity saving, depending on motor and drive characteristics [-];\nSPI is Specific Power Input [kW/(m3/h)];\nth is total hours heating season [h];\nΔΤh is the average difference in indoor (19 °C) and outdoor temperature over a heating season, minus 3K correction for solar and internal gains [K];\nηh is the average space heating efficiency [-];\ncair is the specific heat capacity of air at constant pressure and density [kWh/(m3 K)];\nqref is the reference natural ventilation rate per m2 heated floor area [m3/h.m2];\nηt is the thermal efficiency of heat recovery [-];\nQdefr is the annual heating energy per m2 heated floor area [kWh/m2.a] for defrosting, based on a variable electric resistance heating.\nQ defr = t defr × ΔΤ defr × c air × q net × pef ,\nwhere\ntdefr is the duration of defrosting period, i.e. when the outdoor temperature is below – 4 °C [h/a], and\nΔΤdefr is the average difference in K between the outdoor temperature and – 4 °C during the defrosting period.\nQdefr applies only to bidirectional units with recuperative heat exchanger; for unidirectional units or units with regenerative heat exchanger is Qdefr = 0.\nSPI and ηt are values derived from tests and calculation methods.\nOther parameters and their defaults are given in Table 1.\nTable 1\nSEC calculation parameters\nDefrosting applies only to bidirectional units with recuperative heat exchanger and is calculated as Qdefr = tdefr * Δtdefr * cair * qnet * pef. For unidirectional units or unit with regenerative heat exchanger is Qdefr = 0\ngeneral typology\nMISC\nDucted units\n1,1\nNon-ducted units\n1,21\nventilation control\nCTRL\nManual control (no DCV)\n1\nClock control (no DCV)\n0,95\nCentral demand control\n0,85\nLocal demand control\n0,65\nmotor & drive\nx-value\non/off & single speed\n1\n2-speed\n1,2\nmulti-speed\n1,5\nvariable speed\n2\nClimate\nth in h\nΔΤh in K\ntdefr in h\nΔΤdefr in K\nQdefr in kWh/a.m2\nCold\n6 552\n14,5\n1 003\n5,2\n5,82\nAverage\n5 112\n9,5\n168\n2,4\n0,45\nWarm\n4 392\n5\n—\n—\n—\nDefaults\nvalue\nspecific heat capacity of air, cair in kWh/(m3K)\n0,000344\nnet ventilation requirement per m2 heated floor area, qnet in m3/h.m2\n1,3\nreference natural ventilation rate per m2 heated floor area, qref in m3/h.m2\n2,2\nannual operating hours, ta in h\n8760\nprimary energy factor electric power generation & distribution, pef\n2,5\nspace heating efficiency, ηh\n75 %",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "footnote",
      "label": "f1",
      "text": "Defrosting applies only to bidirectional units with recuperative heat exchanger and is calculated as Qdefr = tdefr * Δtdefr * cair * qnet * pef. For unidirectional units or unit with regenerative heat exchanger is Qdefr = 0"
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/2014/1253/annex/VIII",
    "retrieved_at": "2026-11-01T14:47:08.317179+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}