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 farm’s telehandler.

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 control system which was retained for the existing LPG system as backup.


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.


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 telehandler.

Grant / Funding

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

Savings / Investment

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

Our 90kw ETA Hack wood chip boiler suffered water damage in late 2014. Dunster Biomass Heating was the only company that could fix the issues without costing me new components. What we have learned is simple. Experience is key! When there is an unusual problem you need more than a guy with a manual – you need a company with the expertise, ability and willingness to solve the problem!

Nick Hiscox, Director, GSF Livestock Equipment