England · Statutory guidance
Conservation of fuel and power: Approved Document L, Volume 2 — Buildings other than dwellings
Energy performance guidance for non-domestic buildings, covering fabric, services, controls and commissioning.
- Edition
- 2021 edition incorporating 2023 amendments · Volume 2; later editions and transitions on source page
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- 116 of 116 PDF pages · 2 OCR pages
Energy & sustainability
Open original PDF at page 54 Source wording and page order preserved. Drawings and table layouts remain available in the original PDF.
L1(b), L2 O N L I N E V E R S I O N
6.19 Electric fan convectors should have switching to control both of the following.
a. The local fan.
b. The temperature of individual fan convectors.
Combined heat and power
NOTE: This section of the guidance covers CHP systems that both:
a. have a total power capacity between 5kW and 5MW
e e
b. are used in commercial applications.
For systems with a total power capacity less than 5kW , follow the guidance in Approved
e
Document L, Volume 1: Dwellings.
6.20 CHP plant should, under annual operation, have both of the following.
a. A minimum CHPQA quality index (QI) of 105.
b. Power efficiency greater than 20%.
6.21 CHP plant should have a control system that, as a minimum, ensures that the CHP unit operates as
the lead heat generator. Metering should be provided that measures all of the following.
a. Hours run.
b. Electricity generated.
c. Fuel supplied to the CHP unit.
Dedicated domestic hot water heaters
6.22 The recommended minimum standards set out in this section apply only to dedicated water
heaters. Central heating boilers which provide space heating and domestic hot water should meet
the minimum standards in paragraphs 6.2 to 6.9. Heat pumps which provide domestic hot water
should meet the minimum standards in paragraphs 6.44 to 6.46.
6.23 In addition to meeting the general requirements for heating systems in Section 5, domestic hot
water systems in new and existing buildings should meet the minimum thermal efficiencies in
Table 6.5. Thermal efficiency should include the heat generator and any integral storage vessel, but
exclude the following, where present.
a. Secondary pipework.
b. Fans and pumps.
c. Diverter valves, solenoids, actuators.
d. Supplementary storage vessels.
6.24 Domestic hot water systems should be sized for the anticipated domestic hot water demand of the
building, based on BS EN 12831-3. Systems should not be significantly oversized.
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Approved Document L Volume 2, 2021 edition Building Regulations 2010
O N L I N E V E R S I O N
Edition and local adoption determine which requirements apply. Use the publisher’s document for the complete clauses, diagrams and amendments.