70kW wood pellet boiler
The Abernethy Trust is a Christian educational charity which runs outdoor adventure centres in Scotland. They contacted Dunster to investigate the feasibility of installing a small district heating network for a group of holiday lodges and a pair of staff cottages.
Following a site visit and discussions, Dunster’s scheme to replace the electric heating systems in the properties with heat from a wood pellet boiler installed in an existing garage was accepted. The Trust undertook the initial renovation of the garage, which was in a poor state of repair, after which Dunster installed a bespoke pellet store to make the most of the available space, along with the biomass plant and the distribution pipework.
Dunster designed and installed the interface with each property to allow fully independent control of the heating and hot water supply and worked with the Trust’s plumber who installed the new radiators, hot water cylinders and associated pipework inside the buildings. The installation was carefully phased to minimise disruption to the lodges whilst ensuring that commissioning and RHI accreditation was achieved as soon as practical.
A bulk pellet store has been built into the end of the garage with a V shaped floor and a multi-point vacuum extraction system. The boiler has a ‘day hopper’ which it fills automatically when required and from which it feeds the boiler. No fuel handing is required by the client. About 4 times a year, a pellet tanker delivers fuel to the system by pumping pellets through hoses connected to the filling points outside the building. The boiler does not need to be shut down during filling operations and no access to the plant room is required.
System design and installation
Dunster worked with the Trust’s plumber to ensure that the new radiator and hot water systems installed operated seamlessly with the biomass boiler to maintain maximum efficiency and minimise losses in the external pipework. The 1,500-litre thermal store allows the biomass boiler to operate at peak efficiency even when demand is low in the summer. The networking of the controls ensures that water is only pumped around the system when required, further reducing losses, and allows remote monitoring of the system and reading of all the heat meters over the internet which greatly simplifies billing and data recording.
Pete Moore, Abernethy Trust Deputy Operations Director, said:
"We chose Dunster as they came highly recommended and provided a competitive quote with great detail. Their work was carried out on time and to a high standard. The equipment has proved to be very reliable with minimal maintenance required. The system replaced electric heating resulting in warmer properties that are costing less to heat."
Recent Dunster case studies
Nethybridge Centre – 70kW wood pellet boiler
Gilmour & Aitken Ltd, Scotland – 500kW woodchip boiler
Blervie House, Moray – 205kW woodchip boiler
Beaulieu National Motor Museum – 1.2mW woodchip heating system
Southern Wood Energy – Froling LM KOM-H 1000, woodchip heating system
Southern Wood Energy – Froling woodchip CHP50 Plant
West Country Estate – 130 kW Woodchip District Heating Scheme
Wiltshire Estate – 130 kW woodchip district heating scheme
St Paul’s Church, Weston-Super-Mare – Containerised 140kW wood pellet heating system
Alvie Manse, Inverness-Shire – 35 kW Wood Chip Heating System