Biomass Boilers


For domestic heating purposes the main biomass fuel is wood in the form of logs, pellets or wood chips – although there are boilers available that burn a range of cereals.

How do biomass boilers work?

Wood is hardly a new fuel for heating houses, but the technology has improved considerably to make it more efficient. Open fires may look lovely, but they are not a good way to heat a room. Most of the heat goes up the chimney and, as the fire draws in oxygen to burn, it creates draughts in the room that can cancel out the benefit of the heat.

Biomass boilers can replace oil or gas boilers to heat hot water and radiators (or under floor heating). They burn logs, wood chips, wood pellets or other forms of biomass. The most advanced boilers are fully automatic. They control the amount of fuel and air supplied to the combustion chamber. As a result they are highly efficient and emissions are low.

They are fed with wood chips or pellets from a large hopper sited nearby. If you’ve got space, manufacturers recommend a hopper that’s big enough to hold a year’s supply of fuel. This minimises transport and delivery costs for fuel, as well as work for the owner. Maintenance is minimal – although you will need to clean it and remove the ash about once a month. If that isn’t possible due to space or budget, you can get wood pellet delivered on pallets of 10kg bags, from which you manually fill a smaller hopper.

At the other end of the scale, log-fed boilers are more suitable for people with ready access to a supply of wood, and time to cut it to the right size. These will need more time spent on feeding them with fuel and cleaning out the ash.

Wood pellets are made from compressed sawdust and wood shavings and other biomass products and are uniform in size and shape. They have a higher energy content and so take up less storage space than logs or wood chips. Stove and boiler manufacturers specify the size, shape and moisture content their products need to perform well. Wood pellet systems are the smallest, neatest and most like a mainstream boiler and require the least input from the user.

Wood chips are cheaper and abundant. They allow for more mechanisation than logs, but are not as efficient as wood pellets. It’s important that they are pretty uniform in size to work smoothly in an automated domestic system.

In addition, you will make some savings on fuel costs if you are swapping from oil, LPG or solid fuel, but probably not if you are on mains gas. Wood pellet is currently around 4.8p per kWh, compared with 6.1p for oil, 6.8p for LPG 4.6p for mains gas and 16p for electricity (source: Renewable Energy Installer, April 2014).


Factory Heating

Airflow modular heater is fuelled by wood pellets and is specifically designed for use in Warehouses, Industrial Units and Workshops to provide heating and frost protection.

The Airflow modular unit has been specifically designed for quick and easy

installation. It is mounted on a steel pallet for easy handling with a forklift truck and has minimal requirements for installation.

Requires local electrical supply (single phase), a water supply for filling , level floor suitable for weight of the installed unit, and a suitable biomass fuel