SEDBUK and Boiler Efficiencies
About SEDBUK (Seasonal Efficiency of Domestic Boilers in the UK)
SEDBUK was developed by the Government alongside boiler manufacturers, under their ‘Energy Efficiency Best Practice Programme’. It was designed as a fair basis for comparisons of boiler energy performance when installed in a typical domestic situation in the United Kingdom.
Standard Assessment Procedure (SAP)
To determine boiler efficiencies, a ‘Standard Assessment Procedure’ more commonly known as SAP, is used. SAP is the Government’s standard method for energy rating in the United Kingdom. SAP ratings enable the comparison of energy efficiencies and demonstrate the likely effect of improvements to a property in terms of energy use.
Since SEDBUK was introduced in 1999, it has undergone many changes, the most recent being the move from SAP 2005 to SAP 2009.
The changes between SAP 2005 and SAP 2009 focus on improving the accuracy of the way the efficiencies are worked out. SAP 2009 incorporates a key revision in the assumed carbon emissions per kWh of oil used by the boiler. It may appear that the efficiencies of boilers have reduced with SAP 2009, but it is important to understand that the new methodology gives a more realistic estimate of the average annual boiler efficiency when installed in typical conditions, based on evidence from recent independent testing and field trials.
Up until October 2010, boilers used to rated on a scale of A-G, based on how efficient they were. This was withdrawn, as it was seen as confusing when compared with the proposed European energy label, which has similar ratings, but with different principles.
SEDBUK bands appeared as follows: