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Accumulator tanks

Accumulator tanks

One way to allow optimum firing of your wood fuel boiler is to use an accumulator (buffer) tank.

An accumulator tank is a large, well insulated hot water tank. They are used to manage heat demand variation by allowing the boiler to operate at maximum output to heat a large reservoir of water that is stored until required. The volume of storage in litres should be about 40-60 times the boiler heat output in kW.

They are plumbed in to take heat directly from a boiler, and have a secondary heating coil to take heat and hot water to the rest of the system.

This has the effect of decoupling heat demand from heat production, allowing the boiler to operate at best efficiency and to accept interruptions to the heat supply.

It also allows some leeway in the specification of the boiler, as the accumulator is able to smooth some of the peaks and troughs in demand.