Wood chips are generally classified in terms of size and water content:
Up to G30 / W35 - Some boilers are limited to a very fine grade of wood chip (G30 particle size) and a maximum moisture content of 35%.
Up to G50 / W35 - The majority of boilers are limited to a fine grade wood chip (G50 particle size) and a moisture content of 35%
Up to G100 / W50 - Industrial boilers designed to utilise low cost large particle size of wet wood chips.
Reka boilers of all sizes can be ordered suitable for dry (max W35) or wet fuels (max W50). Standard boilers are suitable for G50 particle size. G100 size can be accommodated on boilers of all sizes but requires the use of a REKA hopper or walking floor fuel systems.
Waste wood fuels can be exempt from WID if they meet certain criteria. For example, clean recycled pallets or wood processing waste can be a very cost effective and environmentally friendly fuel source. The REKA system can handle the inevitable downsides of burning these fuels such as nails and other metal objects which can be successfully carried through the boiler and removed by the heavy duty de-ashing system.
For more information on wood chip and pellet specifications see the resources section