With all types of wood boiler, some ash is produced (usually less than 1% of fuel input). The ash pan needs to be emptied bi-weekly, or less frequently, depending on service. Ash can be disposed of in the garden and is beneficial to plant growth.
Fuel / Storage
Pellets can be purchased in bagged or bulk form. For bulk purchases, a dry covered storage area is required. Generally bulk prices are more competitive than those for bags. Wood chips are generally sourced locally. It is important that the fuel used (quality, size, moisture content) is suitable for the appliance; your supplier will provide you with these details. For pellets, bulk delivery can be arranged to your home where the delivery truck uses a blower to deliver the fuel into your shed, storage room or outdoor silo. 2 tonnes of pellets will deliver the same amount of heat as 1000 litres of heating oil.
Operation and Efficiency
The latest wood boilers offer remote control and monitoring, accessible by mobile phone. It is important that there is adequate ventilation and that a clean air source is supplied to the boiler, as the combustion process uses oxygen (in the same way as any fuel fired appliance). For correct operation and maximum efficiency a hot water buffer store should be supplied with the system.
High efficiency makes economic sense
Wood boilers use the latest technology to control the amount of fuel and air released to the burner. Typical costs of boiler and installation range from €10,000 for 15kW home boiler to a €20,000 for a 100kW boiler for a large building. The lower cost of the fuel competes well with similar oil systems.
Operation and maintenance
Wood boilers operate just like a conventional central heating system and work in conjunction with radiators or under-floor heating. You can control the heating system and regulate the temperature from a panel control. Most reputable boiler suppliers offer service contracts to ensure an optimum operation and long life of the boiler. Many boilers have an automatic system alarm that is sent to a service engineer via SMS messaging on a mobile phone. Quality boiler suppliers report very low failure rates and most problems are solved within minutes, remotely without callout.
Your checklist for selecting a wood boiler
- Efficiency of 85% or higher
- CO2 Emissions less than 200 mg/m3
- After sales service contract
- Automatic cleaning
- Good quality burn back protection
Planning for a wood boiler
- Fuel Storage for 3-4 tonne of wood pellets per year (allow up to 50% more for wood chips due to lower energy density)
- Pellet Storage space of 2 X 3m floor area & 2.25m height (for domestic 15kW boiler)
- Boiler room size of 2m X 2m X 2.5m height
- Select a trained professional installer & supplier