If you belong to a quarter of the Danish households, who lives outside the district heating coverage, you are likely to have another heating heating solution, in the form of oil, or biomass boilers.
If you have an old oil furnace, it might be a good idea to consider a biofuel plant. It is a cheaper solution, and it is more environmentally friendly than oil.
Types of biofuel plant
Biofuel systems are generally designed to use a specific fuel type. It may vary from different of wood-materials to other organic-materials, such as straw or grain. Which material or combustion plant is best for you, depends on your living situation, the size of your home, and how much work you are willing to put into your heating.
The following sections examine the various types of biofuel plants.
Complete combustion heaters, are still the most common boilers in a household, it is typically an older cast-iron boiler, such as the Danish-produced Salamander, Tasso and RIO-boilers, which were very popular until the 1950s, and which still exists in many homes.
How does a Complete combustion work
A Complete combustion heater, is characterized by the combustion air moving from the bottom up, through the fuel layer. The boiler was originally designed for burning coke and oil. In contrast to coke, which is a gas-poor fuel, calls for burning of wood in a much higher temperature and oxygen supply, in order to ensure an efficient combustion of the flue gases. By burning wood, the combustion will produce a lot waste gases with an efficiency below 50%.
Complete combustion heaters are not approved for wood burning
Besides a poor heat economy, an incomplete burning of flue gases also lead to increased air pollution. The unburned gases from the wood, will lead to an increased risk of deterioration or corrosion of the chimney, along with steam from wet wood that will condense in the chimney soot. This will eventually lead to degradation of the chimney and can cause major damage to walls and wallpapers as well as providing a strong odor. There is currently no Complete combustion heaters, which are approved for wood burning, but they can still be bought. One should therefore be aware that they are only approved together with a pellet burner for burning wood pellets or solid fuel in the form of coke and coal.
Rules for boilers
Heating with wood boilers are currently covered by more requirements and rules than before, and with the tightening of building regulations in recent years, rules also apply to boiler efficiency and pollution. Today all biofuel boilers are to be approved and tested, before it can be installed in either new or old households. If you already have a boiler installed, which do not meet the new requirements, you are allowed to continue to use it, if it was installed before January 1, 2006, where the new rules were enforced.
Heating with a wood boiler can be a cheap way to heat your house, but if you have a wood-burning boiler of an older date, it might be time to replace it - both for economical and environmental reasons. A large number of the boilers, installed in the Danish households are in fact not suitable for heating with wood.
Three types of combustion boilers
Today different boilers used for heating with wood, but overall we can distinguish between three different types of boiler complete combustion, Incomplete combustion and reverse combustion.
Find the type approved biofuel boilers
DTI's website contains a list of type approved biofuel boilers. All boilers on the list are tested according to applicable standards.
The boilers on that list has an eco-label and an energy-label. According to DTI, the labels are not an indication that some plants are bad, but just a means to find the most energy efficient and environmentally friendly plants.
About burning boilers undervoltage and reverse combustion
All boilers which are sold today as "approved for wood burning" is either incomplete combustion or reverse combustion.
How does the incomplete combustion boilers work?
In the combustion boilers moving combustion air from the bottom and then backward through the embers without passing the fresh fuel battle.
How does reverse combustion?
Boilers reverse combustion is characterized in that the combustion air is moving from the top down through the filament layer and out through a slot in the bottom of the combustion chamber to a separate combustion chamber. Firewood boilers with reversed combustion is typically expensive - but also the most efficient on the market with an efficiency of over 90%.
Rules for boilers
Heating with wood boilers are currently covered by more requirements and rules than before, and with the tightening of building regulations in recent years made now both requirements for boiler efficiency, and to how much they pollute. Today all biofuel boilers therefore be approved and tested to be installed in both new and old houses. If you have an existing boiler installed which do not meet the new requirements, must be well continue to use it if it is installed before January 1, 2006, when the new rules came into force.
Read the rules on setting up biofuel boilers