The buffer tank: the silent hero of the heating system

If there is an underrated player in heating technology, it is the buffer tank. A large, insulated hot water storage tank, no moving parts, yet this is the element that brings out the inherent efficiency and lifespan of biomass boilers.

Why is a storage tank needed next to the boiler?

The nature of a solid fuel boiler is that it likes to operate evenly, close to its nominal capacity: this is when it burns cleanly, when its efficiency is best, and when it spares itself. The heat demand of the building, however, fluctuates constantly. The buffer tank connects these two rhythms: the boiler produces under optimal operation, the surplus goes into the tank, and the building draws from there when it needs it.

The result is fewer on-off cycles, less tarring and soot, longer boiler lifespan and typically ten to twenty percent less fuel. For a biomass gasification boiler, for example next to a Guntamatic BMK, the buffer tank is not even an option, but a condition for the system's operation.

Which size should we choose?

As a rule of thumb, for wood chip and pellet systems, it is worth calculating 25-50 liters of buffer storage per kilowatt of boiler capacity, while for wood gasification boilers, rather 50-100 liters. For a 100 kW wood chip boiler, a storage tank of approximately 3000-5000 liters is therefore appropriate. The exact size depends on the system design, so it is advisable to consult a specialist during installation.

When buying a boiler, always ask us about buffer options as well: from time to time we also have tanks in our stock, and we can provide recommendations for the system as a whole, not just for the boiler.