The Biomass Boiler
In October 2003, we installed a 120 kW fully automatic boiler to provide enough heat for the main building, offices and the Wetherdown Lodge. Its fuel is literally home-grown: it uses wood from our site.
Some 50 tonnes of seasoned woodfuel per year are sourced locally from local sustainable woodland management operations. The system currently heats the main building and Wetherdown Lodge.
- The installation comprises a Veto 120 kW stoker-boiler, Veto Maxi 6m3 fuel hopper and feed auger and Veto 120 kW burner head.
- Combustion is controlled by a Technomatic modulating boiler controller, optimising combustion according to flue gas oxygen concentration for maximum efficiency and minimum emissions.
- The controller automatically modulates boiler output between 30% and 100% of maximum continuous rating (MCR) to match demand with the boiler, automatically kindling during periods of zero demand.
- Boiler efficiency is greater than 86% (at MCR) and emissions are well within the requirements of the Clean Air Act.
- The boiler is installed in the Lodge boiler house with hot water piped via a pre-insulated underground heat main to the main building's heating system.
- The biomass boiler produces approx 215,000kWh of useful heat each year, avoids 91 tonnes of CO2 emissions each year and uses 82 tonnes of wood chip per year.