Case study

Hellinghayes Poultry Farm

130kW and 200kW woodchip boilers

Key facts


The first boiler was commissioned in February 2013, and after a successful first year, the second boiler was installed in September 2014.


Heating for a total of six chicken broiler sheds.

Boiler and plant

One 130kW ETA Hack woodchip boiler with 3,000 litre accumulator tank and 4m diameter agitator / auger fuel feed system, heating two large broiler houses. Additional 200kW woodchip boiler with 5,000 litre accumulator tank and 5m diameter agitator / auger, heating a further four broiler houses.


The boilers are expected to use around 150 tonnes of wood chip
producing over 525Mwh of heat per annum.

Chip storage

The site allows for a 92m3 walking floor articulated lorry delivery. Wood chip is unloaded into a large barn and then distributed between the two boiler houses periodically with an existing tele-handler.

Grant / Funding

The project was funded partly by own funds and partly through asset finance. Both are accredited separately under the non-domestic RHI scheme.

Savings / Investments

Income from the RHI and fuel cost savings have resulted in
a return on investment of over 18%.

Hellinghayes Farm is a free range poultry farm registered as a ‘Freedom Foods’ producer. The initial project brief was to reduce the LPG costs across the site whilst improving bird welfare through better controlled heating and a drier environment.

Dunster analysed the heating profiles over the entire growing cycle ranging from 32°C at the day-old stage right down to an ambient unheated temperature towards maturity. Heating demands had also to meet seasonal and external temperatures. The key to the whole project was to ensure reliability and control as poultry are highly sensitive to unplanned temperature changes.

Fuel supply and chip handling

Although the farm itself does have access to some woodland this was not enough to sustain both systems. Deliveries are therefore made through a third party fuel supplier by walking-floor articulated lorries, delivering 92m3 per load. This minimises the transport cost. With the woodchip ‘walked out’ into a bulk store this is then transferred periodically to each boilers fuel store by the farms tele-handler.

System design and installation

Dunster designed the biomass and the plant room using our in-house CAD team. Dunster worked with the heat exchanger and control suppliers to ensure the correct specification for each heat emitter. Heat emitters were mounted on specially made brackets to ensure that an even heat distribution was achieved whilst at the same time allowing for them to be moved out of harm’s way during the cleaning cycle.

Dunster designed and built an independent control system for each shed so that temperature control was independent of the Whaler controls retained for the existing LPG system as back-up.


In addition to the attractive 18% return on investment bird welfare has significantly improved due to better heat distribution, a drier environment and drier dander, leading to better returns from happier and healthier birds.

Download Hellinghayes Farm case study

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site design by  TOMODOMO