For biomass fuels, the calorific value (CV) should be obtained from the fuel provider. Only where CV values cannot be obtained from the fuel provider can the following convention be used to produce a DEC; and the assessor must be able to demonstrate that all reasonable efforts have been made to obtain the CV from the fuel provider.
The CV for biomass fuels is dependent on the moisture content which is variable in wood chip fuels so the CV must be calculated as below. Moisture content is more consistent in wood pellet fuels so a fixed CV can be used.
For further information, refer to section 2 (biomass fuels, combustion and emissions) of the CIBSE Application Manual 15-b (AM 15b) 2014.
Wood Chips – option 1: weight-based calculation
The CV (kWh/kg) is calculated as: (Moisture content percentage x -0.0568) + 5
The moisture content must be obtained from the fuel provider.
Mike Gordon
Comments