Wood chip boilers function much like fossil fuel boilers. When heat is required, they will automatically ignite, feed fuel to the fire, and switch off. Their automated nature make them an excellent alternative for those looking for a more cost effective and environmental friendly alternative to traditional oil, LPG, or electrical heating, whilst maintaining the highest comfort levels. Wood chip boilers are generally more suitable for larger domestic and commercial applications where the additional fuel savings compensate for the slightly higher capital cost and greater space and input required for fuel storage. Some models designed for wood chip can also burn wood pellets.
Benefits of a chip burning boiler;
Wood chip boilers require automatic combustion control to adjust to the varying nature of wood chip as a fuel. The most advanced and efficient boilers encompass a lambda sensor to adjust the primary and secondary air for the highest possible efficiencies. The controller ensures the precise mix of fuel, primary air, and secondary air at all stages of combustion to ensure efficiencies of up to 93%.
Wood chip boilers require larger fuel stores than the equivalent sized wood pellet system. Fuel stores should be sized so as to allow the boiler to run for a minimum of approximately 4 weeks in the coldest weather without the need to replenish the store. A number of methods can be used to fill the fuel store and are dependent upon individual sites and equipment available.
Buffer tanks, or thermal stores, are crucial for the efficient operation of all biomass boilers where the heat demand of property can drop below the minimum output of the boiler (typically 30%). Very few properties can guarantee a base load in excess of 30% and therefore buffer tanks should be used to avoid boiler cycling, decreased efficiency, increased electrical consumption, and increased maintenance intervals this causes.