Write-up ( to be published in the Parish Magazine in April 2012)
Three speakers provided an informative insight into three aspects of wood- as a fuel, and wood burning stoves.
Jane Devlin provided the environmental perspective, Rob Walker of Penang Farm talked us through all the aspects of supplying top-quality sustainable wood-fuel and Alex from Bramdean Stoves answered questions about installation, maintenance and servicing of wood-burners.
Did you know that Surrey is the most densely wooded county in England with almost 23% woodland cover compared to the average 11%? But the fragmented nature of ownership of these woodland makes it difficult to open up the woodfuel supply market: in the South East region, 40% of the woodland is owned by around 14,000 individual private owners and farms. Well-managed woodland can provide sustainable fuel that avoids the damaging carbon emissions caused by burning fossil fuels like coal. More than that, well-managed woodlands are perfect places for wildlife and biodiversity, which in turn make them wonderful for recreation, too. Also covered – how to zone your home using wood-burners to reduce costs and carbon emissions, and all about local initiatives in the Surrey Hills AONB to initiate more woodland management for wood-fuel and biodiversity.
Harvesting the wood and turning it into logs involves some big, and expensive machines. Rob Walker showed a set of slides illustrating how the process of seasoning takes up to two years. He brought samples and explained how different species of tree – oak, ash, beech, sweet chestnut and even eucalyptus – are stored and cut, transported and stacked for the best results. Rob gave lots of tips to note when buying logs, such as checking the size of the load,
what price to expect for different qualities. Moisture content of freshly cut wood or ‘green’ is about 40% which means it will not burn easily, if at all. By leaving the timber to dry out over a season or two in specially designed sheds with open slats for air circulation, the moisture content decreased to 20%, and the calorific value, or heat it generates when burned increases. He recommends having a moisture meter to verify moisture content. This hand held, battery operated device costs about £20.
Alex from Bramdean Stoves is well-used to answering questions from customers in the showroom in Haslemere. With lots more questions from the floor, all the important aspects of choosing the right sized stove for your room, installing a chimney or flue liner, and ensuring that the relevant building regulations are complied with. He explained that chimneys older than 10 years were built before the current Building Regulations requirement for a concrete of ceramic flue liner came in, and will definitely need a liner. The construction and intallation incorporates insulating the chimney from the metal liner to avoid the corrosive effect of heat on brickwork and mortar. Unlined chimney problems include tars seeping through the mortar and plaster, causing unsightly staining which is almost impossible to remedy. A lined flue improves the ‘draw’ and helps to minimise condensation of flue gasses onto the sides. He told us about the importance of using a HETAS certified installer. If your flue liner were to to be accidental installed upside-down for instance, the chimney might clog up with condensing flue gases and catch fire. Sweeping the chimney though the stove is straight forward, even if the pipe doesn’t look straight. connector pipes are designed to allow access for cleaning and maintenance There is very little to go wrong with a wood-burner, even the fire-bricks can be replaced easily for about £20. We talked about air vents and controlling the heat output of wood-burners. They are about 80% efficient, compared with an open fireplace at about 20%. This means that too much heat might be a problem, but Alex explained how he manages to regulate the heat output of the stove in the showroom by varying the amount of fuel in the stove, and by controlling airflow.
Many Thanks to Rob and to Alex for an excellent and thorough coverage of using wood and wood-burners to heat your home.
Jane Devlin 21 March 2012