Blervie House, Moray
205kW woodchip boiler
Blervie House was heated by over 100 electric night storage radiators resulting in fuel bills exceeding £1,000 per month even in summer. As part of a renovation project, Dunster was approached to design an integrated, multi-zone heating and hot water system to allow the house to be heated effectively and affordably for the first time in its history.
To minimise the impact on the listed building, and to keep chip handling machinery away from the house, the boiler and associated plant were installed in a new timber building approximately 100m from the house. This was connected to the house by buried, pre-insulated district heating pipe. Within the house, state of the art controls provide weather compensated heating and ensure that it is a simple matter to adjust temperatures to match the demands of variable occupancy. Although still part of the networked system, the housekeeper’s flat has been set up with its own controls and heat meter so that the occupant can have complete control of heating and hot water timings and temperatures.
Fuel supply and chip handling
The chip hopper forms an integral part of the building which holds the biomass boiler and associated plant. It is loaded from the adjacent bulk chip store using a tractor and bucket and can hold enough fuel for around 3–4 weeks heating in winter and around double that in summer. Initially, wood chips were bought from a local supplier but estate timber is being seasoned and, once dry, will be chipped directly into the bulk store by a contractor.
System design and installation
Dunster worked with the client’s M&E consultant to specify the main heating plant and ensure that the new radiator and hot water systems installed in the building operated seamlessly with the biomass boiler to maintain maximum efficiency and minimise losses in the external pipework. The 5,000 litre thermal store allows the biomass boiler to operate at peak efficiency even when demand is low in the summer whilst the 100kW oil boiler, which was installed as a back-up system, has not been required in the first year of operation.
In addition to the CO2 savings and a return on investment of over 15%, the low cost of heat and the sophisticated controls allow unoccupied areas of the house to be provided with background heating which greatly benefits the fabric of the building and improves habitability. By using a wood chip fuelled system, costs are kept to a minimum and there is also an economic incentive to actively manage the estate woodlands which has much wider environmental benefits. The client particularly appreciates the ability to monitor and adjust all elements of the heating system using his mobile phone and has been impressed by the simplicity and cleanliness of its operation.
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