Buffer Tanks Explained – As we move away from conventional Gas and Oil fired boilers and towards more economical Biomass & Wood Burning Boilers, we need to think differently about our Hot Water Storage and how we utilise them.

Gas and Oil fired Boilers supply almost instant heat when they ignite, so we can rely on them to supply on demand hot water when required. Our thermostats tell these boilers that we need heat and they obey, sending the heat to either our radiators, underfloor heating or domestic hot water cylinders. Simple.

However this does not apply to Biomass Boilers or Wood Burning Stoves. For a Biomass Boiler to work efficiently it needs more time to heat up, so it prefers to come on for longer periods of time. It is a very effective and economical system of supplying heat, but only if they are allowed to burn for fewer but longer burning periods. Therefore we have a problem to deal with. While the Biomass is burning we have more heat than we immediately need, so therefore we have to store this surplus heat. This heat can then be called upon as required. So the solution is a Buffer Tank.

A Buffer tank is like a water version of a car battery storing up electricity until the car engine needs the reserve of power to start the engine. We need immediate heat for our radiators or our domestic hot water, so that heat is taken from the Buffer Tank while the boiler is idle. The Buffer Tank can store a large amount of energy, so the boiler only needs to fire up maybe 4 times a day instead of 20 or 30 times a day as with a gas or oil fired boiler.

A buffer tank is also known as an Accumulator or Thermal Store. Each can come in many sizes and have a varying number of internal heat exchange coils to connect to other heat sources such as Solar Thermal.

It is important to size the Buffer tank correctly depending on the size of boiler and your demand. Green Phoenix can help with sizing your tank correclty. Call 01225 580 840 today.