Conservation of fuel and power: Approved Document L, Volume 2 — Buildings other than dwellings

O N L I N E V E R S I O N L1(b), L2 Section 6: System specific guidance NOTE: This section sets out minimum Building Regulations standards for fixed building services and other systems. Best practice is to achieve higher efficiencies than these minimum standards. NOTE: The Ecodesign for Energy-Related Products Regulations 2010 set the efficiencies and standards that must be met when introducing new energy-using products to the market. This approved document sets standards that should be met when installing fixed building services or on-site electricity generation. In cases where the Energy-Related Products Regulations and the Building Regulations both apply, both standards should be met. 6.1 This section sets out minimum standards for specific types of building services. The minimum efficiencies set out are based on documented manufacturers’ test data. Note that test results will always be based on the equipment’s operation under particular conditions. Equipment should be designed, specified and installed with the aim of maximising its efficiency as-installed. Boilers NOTE: This subsection applies to wet central heating systems that use commercial boilers fired by natural gas, liquid petroleum gas, oil or biomass. Steam boilers are not covered. Electric boilers are dealt with in a separate subsection. 6.2 In addition to meeting the general requirements for heating systems in Section 5 and following paragraphs 6.7 and 6.8, a boiler should meet either of the following. a. For new buildings, the seasonal efficiencies in Table 6.1. b. For boiler plant installed in existing buildings, the seasonal efficiencies, or the overall seasonal efficiency for multiple-boiler systems using non-identical boilers, in Table 6.2. Table 6.1 M inimum heat generator seasonal efficiency for boiler systems in new buildings(1) Fuel type System Boiler seasonal efficiency (gross calorific value) Natural gas Single-boiler ≤2MW output 93% Single-boiler >2MW output 88% Multiple-boiler 88% for any individual boiler 93% for overall multi-boiler system NOTE: 1. Seasonal efficiencies should be calculated in line with paragraphs 6.3 to 6.6. 39 Building Regulations 2010 Approved Document L Volume 2, 2021 edition O N L I N E V E R S I O N