# The Ecodesign for Energy-Related Products and Energy Information (Lighting Products) Regulations 2021, Paragraph 1


The energy efficiency class of light sources must be determined as set out in Table 12, on the basis of the total mains efficacy ηTM, which is calculated by—
(a) dividing the declared useful luminous flux Φuse (expressed in lm) by the declared on-mode power consumption Pon (expressed in W); and
(b) multiplying by the applicable factor FTM in Table 13,
as follows—
ηTM = (Φuse/Pon) × FTM (lm/W).
Table 12
Energy efficiency classes of light sources
Energy efficiency class
Total mains efficacy ηΤM (lm/W)
A
210 ≤ ηΤM
B
185 ≤ ηΤM < 210
C
160 ≤ ηΤM < 185
D
135 ≤ ηΤM < 160
E
110 ≤ ηΤM < 135
F
85 ≤ ηΤM < 110
G
ηΤM < 85
Table 13
Factors FTM by light source type
Light source type
Factor FTM
Non-directional (NDLS) operating on mains (MLS)
1.000
Non-directional (NDLS) not operating on mains (NMLS)
0.926
Directional (DLS) operating on mains (MLS)
1.176
Directional (DLS) not operating on mains (NMLS)
1.089

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Source: https://www.legislation.gov.uk/ukdsi/2021/9780348225488/schedule/12/paragraph/1 (the official version)
Page: https://openlegislation.uk/draft-ecodesign-for-energy-related-products-and-energy-information-lighting-products-regulations-2021/schedule-12/paragraph-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.