Open fires are inefficient and are not a good way to heat the home. 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.
Modern biomass stoves and boilers are a huge improvement on the open fire for room heating. They convert 70 per cent of the fuel into useful heat. Smaller biomass stoves can be used just for room heating, many having a back boiler to produce hot water and heating for the whole house.
So what is a biomass heating system?
Biomass boilers burn; logs, wood chips, wood pellets or other forms of biomass. Instead of using oil or gas powered boilers to heat the domestic hot water and wall mounted radiators (or under floor heating). Today, the most advanced biomass boilers are fully automatic and control the amount of fuel and air supplied to the combustion chamber. As a result, they are highly efficient and can result in lower energy bills and emissions.
The financial savings that can be made from a biomass heating system are achieved through this energy efficiency and can be further increased with good home insulation. Biomass heating systems are also eligible for the government's Renewable Heat Incentive.
Fuel & maintenance requirements
The most popular fuel for domestic biomass heating systems tends to be wood; in the form of logs, pellets or wood chips. Biomass boilers are fed with wood chips or pellets from a large hopper usually positioned nearby. If you have space, manufacturers recommend a hopper that's big enough to hold an entire year's supply of fuel. This reduces the transport and delivery costs for fuel, as well as limiting the work for the owner.
Maintenance of these boilers is minimal, although you will need to clean it and remove the ash about once a month.
At the other end of the scale, log-fed boilers are more suitable for people with ready access to a supply of raw timber and the time to cut it down to size. These will need more time spent on feeding them with fuel and cleaning out the ash.
Automatic Pellet Stoves
Automatic pellet stoves are even more efficient and usually operate at 85 to 90 per cent efficiency. They spread the heat through convection, rather than traditional radiation - which means the room is heated more evenly and efficiently using a fan. A back boiler can also be added if desired.
These are clean and very easy to use with automatic ignition and a thermostatic control. They also tend to have an integrated hopper which automatically tops up the fuel: these stoves generally hold enough fuel for one to three days operation.
Biomass System - costs
A pellet stove will cost around £4,300 including installation. Installing a new log stove will usually cost less than half this, including a new flue or chimney lining.
For boilers, an automatically fed pellet boiler for an average home costs around £11,500 including; installation, flue, fuel store and VAT at the reduced level of 5%. Manually fed log boiler systems can be slightly cheaper.
Pellet costs depend mainly on the size and method of delivery. Buying in bulk is usually less expensive. If you have large storage space that can hold many tons of pellets, the cost can be kept down to approximately £190 per ton.
Benefits of domestic biomass heating
- The price of wood fuel is often cheaper than other fuels for alternative systems, and is considerably cheaper than; coal, electricity, oil or LPG (Liquid Petroleum Gas, such as; Calor Gas).
- Biomass fuel boiler and stove systems can often benefit from the Renewable Heat Incentive.
- Lower carbon footprint, carbon dioxide emissions are significantly lower, between 4 tons to 7.5 tons depending the type of fuel being replaced.