In the 21st Century, protecting the environment has become a major issue which has become increasingly hard to ignore. The need to find renewable energy sources and sustainable ways of living have never been more important to the everyday individual and, when it comes to heating, this concern is no different.
There are currently over 1.5 million households in the UK with a wood burning stove and nearly 200,000 stoves are sold annually. Over the last few decades this large proportion of wood burning stoves has caused some concerns amongst Government institutions, local councils and environmentalists alike.
As recently as September 2017, Sadhiq Khan proposed a ban on wood burning stoves in certain areas of London at certain times of year. Thought to be introduced by 2025, this ban was prompted by fears that particles produced in smoke and other emissions may lead to lung cancer, heart conditions and even death. As part of the Sadihiq Khan’s plan, homeowners that do not conform to these ‘smoke-free’ zones could be fined up to £1000 and all but the most eco-friendly, low-emissions stoves (EcoDesign Ready) would be prohibited from being sold after 2022.
Although there has yet to be an approval of the London Mayor’s plans from the Government, support for his proposals from the Green Party and Client Earth couple together with the ever present threat of air pollution and global warming means that something does have to be done to cut the emissions of wood burning stoves.
With the creation of smoke free zones in most large UK cities and this recent proposal by the Mayor of London, it would at first appear that burning wood is one of the least sustainable or ‘eco-friendly’ means of heating your home. However, in reality the truth is quite different and you may be quite surprised at how ecological they actually are and what you can do to help them produce less harmful emissions.
Logs vs Fossil Fuels
The first key element which makes log burning stoves far more eco-friendly than gas or electric heaters, is the fuel itself. Wood is a carbon-neutral fuel which means it does not produce more carbon dioxide (CO2) than is already present in the carbon cycle. Any CO2 that is produced by burning wood is simply reabsorbed by plants and trees and converted back into oxygen or stored as CO2 in the plant.
Fossil fuels, on the other hand, produce far more CO2 when burned and increase the amount presently current within the carbon cycle, the condensed carbon having been locked inside them for millions of years and being released into the atmosphere. Therefore fossil fuels are not carbon neutral and can harm the environment in a way burning wood could never match. Furthermore, most coal and other fossil fuels also have to be imported, only adding further to their carbon footprint. By choosing to burn wood you are already helping the environment.
Aside from being carbon neutral, the kinds of emissions given off by burning wood are far less harmful than those given off by fossil fuels. What we commonly call air pollution is made up of several particles and gases, the most harmful being CO2, NOx and PM2.5. In terms of climate change and damage to peoples’ health, it is CO2 and NOx which are the key dangers and need a reduction in their production and unsurprisingly it is the burning of fossil fuels which contribute to this the most. Gas and cars are the biggest producers of these dangerous gases, with 38% of central London’s emissions being produced by gas heaters alone.
When compared to gas and electricity equivalents, which produce 0.198 kg and 0.517 kg of CO2 per kWh respectively, modern wood burning stoves only produce 0.008 kg, clearly demonstrating the environmental benefits of switching to a stove. Not only do they produce less CO2 than fossil fuels, they also produce so much heat that you can quite easily heat a room and the rooms around the stove with the log burner alone, with no need to use up fossil fuels heating up your central heating system. This means that you are not only saving the planet but also saving a lot of money on your heating bills.
Of course some multi-fuel stoves can burn fossil fuels, in the form of coal, however this has become an increasingly unpopular means of running stoves as coal not only produces more CO2 than wood but also a lot more smoke, something that has become a major issue in many urban areas. Smokeless coals have been developed and these do indeed reduce the amount of smoke released during combustion. However, when compared to burning wood, even smokeless coal falls short in terms of efficiency and sustainability.
It can also be argued that, whilst more sustainable and eco-friendly than fossil fuels, burning wood can still harmful to the environment due to the amount of particle matter (PM2.5) they produce. However, the key issue, and particular in the example of London above, is that it is not necessarily log burning stoves which are contributing to air pollution the UK to a serious degree. 70% of wood burnt in the city is used for open fires which produce far more emissions than their stove counterparts and are far less efficient. In contrast, most EcoDesign Ready stoves can reduce emissions by up to 90% when compared to open fires and make the most out of the fuel they burn. Furthermore, levels of PM2.5 are increasingly being cut by these modern stoves, with many of the factors contributing to their EcoDesign Ready status originating in their ability to reduce particle matter production, and hence air pollution.
Seasoned Wood and Briquettes
Yet burning any old wood is not necessarily the most ecological way of fuelling a wood burning stove. To make the most out of your stove and ensure you are causing as little of an impact on the environment as possible, it is important to understand the type of wood you should be burning and even more eco-friendly alternatives.
The type of wood you should burn on a wood burning stove should be dry and seasoned. This means that the fire does not have to work hard to combust the material given to it and, hence produces less smoke. In terms of efficiency this means that your stove will heat up quicker and produce far more heat than damp or unseasoned wood.
The most efficient and environmentally friendly humidity for logs is under 20% whilst newly cut logs can be as high as 60%. To counter act this, leave new logs in a dry place with plenty of air circulation for over a year and, if you want to improve this further you can buy kiln dried logs which have a moisture content of around 18%.
An even better alternative to seasoned wood is the use of briquettes to fuel your stove. These compact pieces of fuel are made up of pieces of old waste wood, harvested from broken furniture and other disposable wood sources.
By their very nature briquettes have the qualities of dry and seasoned wood however they are much more efficient and cost effective. Briquettes produce roughly 50% more heat for each pound spent on them when compared to logs and can last up to four hours. This is helped by the fact that most briquettes have a moisture content of below 10%, furthering their burning capabilities and ensuring they produce the most heat they can for the least amount of smoke and CO2. Furthermore, because of their incredible efficiency and heat production, the use of briquettes instead of logs could save you up to £150 a year when purchasing fuel for your log burner.
Eco-stoves and EcoDesign Ready
Whilst burning wood rather than coal, and using a stove over traditional central heating systems can be more efficient and ecological for your home, there are even more eco-friendly alternatives to the conventional wood burning stove.
In the last decade the development of the ‘eco-stove’ has been a major breakthrough in ensuring stoves can be as environmentally friendly as they can be.
Certified by DEFRA (Department of Environment, Farming and Rural Affairs) in meeting Government standards on air pollution, these stoves differ to their predecessors as they try to prevent the fire from being starved of air as much as possible. Via secondary and tertiary air in-takes, these stoves ensure air gets to the fire, and hence, ensures that it gets the oxygen it needs to burn at maximum efficiency. Not only does this mean that the fuel inside the stove produces the most heat it can, but also it reduces the amount of smoke produced by the fuel as a result if this efficient combustion.
Eco-stoves always burn at over 70% efficiency and help keep your chimney clean due to their lack of smoke output. Compared to open fires, which have a minimum efficiency of 40%, it is clear to see the immense difference this can have in heating your home. Their minimal smoke production is also a huge benefit as this does not only help the environment but also allows air to flow down in to the fire, feeding it and increasing efficiency even further. Not only will these factors help you keep air pollution down and smoke levels low in urban environments, but they will also save you a lot of money on your heating bills and chimney sweeping.
In the coming years, older forms of wood burning stove are expected to be phased out and re-placed by these eco-stoves. Tests by the SIA (Stove Industry Alliance) found that eco-stoves reduced particulate emissions by between 80-84% when compared to older models and the independent standards body for heating appliances, HETAS, is heading a campaign to make sure all wood-burners can be as efficient as possible.
These new eco-stoves are at the heart of the SIA initiative to limit the amount of emissions produced by wood burning stoves. This initiative aims to give an EcoDesign Ready label to most modern Eco-stoves, a label which verifies the low-emission status of the stove in line with requirements outlined in Regulation (EU) 2015/1185 24/5/2015 regarding EcoDesign solid fuel heaters. In partnership with HETAS, the SIA aims to lower emissions further on EcoDesign Ready stoves and meet the ever more stringent guidelines imposed upon them before 2022.
With rising concerns over the impact of fossil fuels on the planet’s atmosphere and the increasing problem of CO2 and smoke levels in cities, eco-stoves look set to be the most efficient and eco-friendly alternative the standard wood burning stove. In the future, only stoves with the EcoDesign Ready label will be able to meet the demands placed on lower-emissions and smoke production and, due their incredible efficiency, these stoves, if fuelled correctly, may prove to be more ecological than your central heating.