Gloucestershire firm Windhager UK has launched a Duowin combination biomass boiler that provides heating from wood and pellets in one unit.
A fuel-switching system detects when the wood gassifier is in burnout and switches to pellet operation, either automatically or at a chosen time.
The Duowin is based on two of Austrian firm Windhager’s biomass boilers, the compact Logwin Klassik and the recently launched compact Biowin 2 wood pellet boiler. It takes up only 4.19cu m of space.
It is available in either a comfort or energy-optimised form with a power boost function to meet short-term higher heat demands up to 56kW.
With the energy-optimised version, the Duowin’s pellet operation is said to be up to 25% more efficient than conventional combination boilers.
It is available in four models from 33-56kW output, with a filling volume of 145 litres for 50cm split logs and 164 litres of wood pellets. The feed can be either manual or fully automatic.
Within the unit there are two independent heat exchanger systems that are claimed to give good reliability, but require less space compared with other combinations.
Both the wood combustion chamber and the stainless steel pellet burner bowl are non-wearing parts and are included in Windhager’s five-year warranty. Users can also upgrade at any time to the Duowin if they have Windhager’s Logwin Klassic log boiler.
The Logwin Klassic has a large filling chamber opening for good access with logs and a detachable ash pan for easy removal. The log boiler also has automatic ignition, so no kindling is required to start the boiler burning.
Starting price for the Duowin is £14,500 including VAT, installation costs or other accessories. In a non-domestic installation qualifying for the RHI scheme the payback for this installation can be as short as five years.