For ecological and political reasons, the building owners no longer wanted to use an oil-fired boiler, but cost-benefit analysis was against the use of a heat pump.
In response to an approach from Griesser Installation AG, Hoval developed a boiler for field testing.
The existing oil tank for the project became the storage room for 7 t of wood pellets. Using an Archimedian screw and turbine, pellets are delivered to the boiler.
The boiler has automatic ignition and control of combustion air using a variable-speed fan that enables output to be modulated from 50 kW down to 15 kW. Noise levels are comparable with the previous oil-fired boiler.
There are plans to develop heating products using pellets with outputs from 70 to 100 kW this autumn.
