Boilers & SEDBUK

Boilers provide heating for space and water, and are assessed in the SAP calculation for both efficiency and the carbon emissions caused by the production of the fuel employed; oil, gas, electricity, or LPG.

The Seasonal Efficiency Database of Boilers in the UK - SEDBUK - was developed under the Government's Energy Efficiency Best Practice Programme with the co-operation of boiler manufacturers, and provides a basis for fair comparison of the energy performance of different boilers.  The project took place over a period of three years, during which a theoretical seasonal efficiency ‘model’ was developed for simple boilers and then adapted to include other types. Experimental data obtained from detailed laboratory tests on over 20 different boilers, supported by data from field trials in 99 homes, was used to validate the theoretical assumptions. This allowed fuel usage data (termed "signature") to be related to efficiency test results supplied by manufacturers.  

SEDBUK is the average annual efficiency achieved in typical domestic conditions, making reasonable assumptions about pattern of usage, climate, control, and other influences. Included in the calculations are other important factors such as boiler type, ignition arrangement, internal store size, fuel used, and knowledge of the UK climate and typical domestic usage patterns.

For estimating annual fuel costs SEDBUK is a better guide than laboratory test results alone. It can be applied to most gas and oil domestic boilers for which data is available from tests conducted to the relevant European standards. The SEDBUK method is used in SAP.

The purpose of the project was to develop a method for calculating seasonal efficiency for individual central heating boilers to use in the UK Building Regulations, Part L (Conservation of Fuel and Power).

As a simple guide to efficiency, a scheme has been created with SEDBUK efficiency bands assigned to boilers on an "A" to "G" scale. The band is shown in the SEDBUK database and may be used on product literature and labels, though there is no requirement for manufacturers to do so. The labelling scheme is temporary as it will be withdrawn when a European directive on boiler energy labelling is introduced.

• Thermal Properties
• Thermal Mass
• Thermal Bridging
• Cylinders & Measured Heat Loss
• Dimensions
• Boilers & SEDBUK (Seasonal Efficiency Database of Boilers in the UK)
• Ventilation Systems & the Appendix Q database
• Solar Gains
• Insulation
• Space Heating Systems
• Water Heating Systems
• Low Carbon Power Souces
• Condensation & Dewpoint Analysis
• Heat Pumps