Wood Pellet Biomass Boilers (condensing)
Wood pellet boilers (Biomass Boilers) are an environmentally friendly, safe and convenient way of heating the home, using wood pellets as fuel.
However, they differ from traditional solid fuel boilers. Apart from the green aspect, the units are fully automatic and behave more like an oil or gas boiler, using advanced controls which cleverly regulate the amount of fuel being delivered to the burner to match the heat demand on the boiler. The fuel is fed to the burner via an auger connected to the adjacent pellet store/hopper. This can, in turn, be automatically supplied from a bulk pellet store which can vary in size.
The process of burning wood produces ash, so wood pellet boilers, biomass boilers normally require a certain amount of regular cleaning and maintenance, which can be tedious. Grant has, however, found a better solution with their unique ‘self cleaning’ boiler design, reducing the need for cleaning to once a year under normal running conditions.
A unique and efficient biomass boiler
Single units are available in outputs of 6-26kW with an efficiency of 97.4%, and 9-36kW with an efficiency of 93.1%. They come complete with a pellet store/hopper and feed auger, which automatically supplies the Spira with fuel.
Grant has also extended the output options of the Spira to enable installations up to 72kW to be accommodated, utilising two boilers and a central hopper/twin auger arrangement. Models include 12-52kW, 15-62kW and 18-72kW. Using two boilers to achieve higher outputs is very cost effective, as when the units are combined in this way their precise electronic burner controls allow both units to modulate as one, down to just 25% of maximum load when the full output is not required. This, combined with the extremely high condensing efficiencies achieved, makes the Spira a unique option when considering a biomass boiler.
How the boiler works
On start up the auger feeds the wood pellets from the hopper into the burner where it is lit by an ignition element. The burner output modulates to achieve the set temperature by controlling the feed rate of pellets. The fan in the burner propels hot gas generated from the fuel into the Spira’s primary heat exchanger. The heat energy is then transferred to water from the central heating system, before being circulated around house to radiators/underfloor. It is important to note that in modern pellet boilers, biomass boilers, up to 20% of the energy that is produced is lost to the atmosphere through waste gases exhausted by the flue system, The Spira has a unique secondary condensing heat exchanger which has been designed to capture some of this lost latent heat enegy, so it can maintain extremely high efficiencies. The boiler’s fully automatic cleaning system will periodically wash the condensing unit of any debris in the tubes and also activate the brazier within the burner to clear the combustion chamber of ash build up, which reduces maintenance time.
DEFRA list of appliances with exemption under the Clean Air Act
Both the Grant Spira 6-26kW and Grant Spira 9-36kW Condensing Wood Pellet Boilers are now detailed on the DEFRA list of appliances with exemption under the Clean Air Act. This allows for the appliances to be installed in urban and city locations without contravening the Clean Air Act 1993. For more information, please click here.
|WPS626 RH110||6-26kW||26kW wood pellet boiler c/w 110kg right hand single hopper and feed auger|
|WPS626 LH110||6-26kW||26kW wood pellet boiler c/w 110kg left hand single hopper and feed auger|
|WPS626 RH200||6-26kW||26kW wood pellet boiler c/w 200kg right hand single hopper and feed auger|
|WPS626 LH200||6-26kW||26kW wood pellet boiler c/w 200kg left hand single hopper and feed auger|
|WPS936 RH110||9-36kW||36kW wood pellet boiler c/w 110kg right hand single hopper and feed auger|
|WPS936 LH110||9-36kW||36kW wood pellet boiler c/w 110kg left hand single hopper and feed auger|
|WPS936 RH200||9-36kW||36kW wood pellet boiler c/w 200kg right hand single hopper and feed auger|
|WPS936 LH200||9-36kW||36kW wood pellet boiler c/w 200kg left hand single hopper and feed auger|
|WPS1252||12-52kW||2 x 26kW wood pellet boilers c/w 140kg dual hopper and feed augers|
|WPS1562||15-62kW||26kW & 36kW wood pellet boilers c/w 140kg dual hopper and feed augers|
|WPS1872||18-72kW||2 x 36kW wood pellet boilers c/w 140kg dual hopper and feed augers|