With the last hints of summer clinging on by a sunbeam, it’s becoming painfully obvious that winter will soon be upon us. This cheery thought has led me to writing an article about wood burning stoves. Now I know that when you think of energy saving and environmental issues, burning wood isn’t the first thing that springs to mind; but do remember that wood is essentially a renewable energy source. With that in mind I would like to take a look at the more domestic side of wood burners. You know; those little black stoves that sit in a corner looking all cosy and warm with a ring of the Dickensian Christmas about them.
Why buy a wood burner?
First of all, wood is a carbon-neutral fuel. If the forest that that the wood comes from is managed in a sustainable manner (i.e. as one tree is felled, another one is planted) then the carbon released by burning the wood is taken up by the growing of the new tree. Even better, it’s possible to source your wood from a tree surgeon who sells wood from trees that have to be cut down anyway, perhaps due to disease or the fact that they just got too big. This avoids the monoculture often associated with managed forests and you can rest assured that you are burning what is essentially a waste product.
But – I hear you ask – how can installing a wood burner save energy and reduce carbon emissions? Well, if you have ever been to house that has a wood burner you will already know the answer to that question. If however you haven’t, I can tell you; a correctly sized burner running at full pelt can easily heat up a room, maybe two. This means that radiators (or other heating systems) in the vicinity become redundant, thus saving on the gas/electricity used to power them. Another advantage comes around the time of year when the temperature starts falling and the hands are teetering over that central heating button, debating whether or not turn it on. At this point a wood burner can provide just enough heat to keep you going for a few weeks and delay that first turning on of the radiators, again saving on heating bills and carbon emissions. You can also boil a kettle on some models (those with a rear discharge), which has the double bonus of saving electricity and also making the room feel warmer because of the increased humidity.
Can any house have a wood burner?
Yes, although wood burners are usually best fitted into an existing fireplace that is not being used any more. Because of its natural recess and existing hearth and chimney, an unused fireplace has all the ingredients required to simply slot a wood burner into where the original fire once resided. When I say simply, I am or course talking in relative terms. Before a wood burner can be fitted, it is essential that that chimney be checked for damage. It is almost always that case that a liner will then need to be inserted and then a professional must come and fit the burner. The reason a flue has to be inserted into a chimney that was originally designed for a roaring open fire is that the wood burner burns slowly and the exhaust gases aren’t as hot as those of a fire. The result is that sticky creosote can build up on a stone or brick chimney, whereas this is less likely in a metal flue.
If you don’t own a property with a fireplace you can still have a wood burner, but you’ll need to have a twin wall flue installed. This is where the flue runs to the outside of the property and then straight up the exterior wall. An advantage of this is that you can place the stove wherever you want it in the house, so long as an exterior wall is accessible. In some cases, it may actually be cheaper to have a twin wall flue put in even if the property does have a chimney, because if the chimney is defective then having it fixed may not be cost-effective.
If you live a smokeless zone, for example within a city, then you will need to make sure you purchase a clean burning stove. Basically this is a wood burner that is so efficient at combustion that the emissions are low enough for it to be approved in a smokeless zone. When you buy one of these exempt appliances, you will receive a certificate to show that the burner meets DEFRA’s emission levels test. This is a perfect solution if you have a fireplace and working chimney, but don’t want to burn smokeless coal. On that subject, it is possible to buy multi-fuel stoves that will also burn coal, but that releases carbon, so I’m not going to go into those here.
Some tips on getting your wood
First and foremost try and season your wood, and I don’t mean putting salt and pepper on it. Seasoned wood is that which has had time to dry – usually for a minimum of 6 months. If have room to store it – a woodshed or such like – then buy your wood in the summer ready for use in the winter. The reason for this is that wood with moisture content can lower the efficiency of a wood burner by 50-60%, in effect turning a 5KW burner into a 2KW burner. This is because the energy from the fire is going into ridding the wood of its moisture before actually burning it. You will also create condensation, which can prove problematic for flues. By far the best wood you can buy is kiln-dried, which has moisture content of about 20% or lower. They are more expensive than normal logs but will last you longer and burn with a greater efficiency, thus negating the higher prices. Do note though; kiln-dried wood is the best for burning, but the drying process will raise its carbon footprint, so you do need to consider that when buying your wood. One thing that you can burn, albeit in small amounts, is demolition timber. The best thing about this wood is that it’s completely free to gather, so long as you are little crafty and don’t mind rummaging around in skips; although like my chimney sweep says; you meet the nicest people skip-raiding.
Eco logs
One potential fuel source for wood burners – or open fires for that matter – are Eco Logs. These are wood ’bricks’ that are made by mechanically compressing sawdust and wood shavings from forests and sawmills (there are no chemicals used to make the logs). Because of the even distribution of the compressed wood and low moisture content, it is claimed that these logs will burn for 2-3 times that of a normal log. Due to their regular shape they also take up less room, making them easier and less costly to transport and store. Eco logs are little more expensive to buy, but the long burn times and fact that they are made from waste products makes them well worth a look. There are many suppliers on the net.
Costs
Installation – The biggest cost is the getting the chimney lined, which will cost you around £1000. After that the price will be relative to the type and size of the burner you require. As a guide, a room of 20 square metres will require a stove of about 4KW. For a standard model you are looking at about £300. If you add in the fitter’s labour charge, you’re looking at a total of approximately £1600 to install a burner. Not bad really.
Fuel – Prices can vary wildly for this, depending on the type of wood you buy. Seasoned wood is more expensive than fresh and kiln-dried is more expensive again. You can get a bag of 10 seasoned logs for about £2.50 – £5.00. If you can, buy in bulk because as you increase the amount of wood you buy, the price will drop.
Maintenance – The chimney must be swept at least once a year at a cost of around £40. Apart from that, if you keep the stove clean, then you should have years of trouble-free burning.
It’s about now that I would usually tell you how much money you can save and what the payback time could be if you choose to purchase whatever I may be writing about. This time however, I have to say it’s unlikely you will save any money – energy and carbon; yes – but not money. This is down to the fact that if you do purchase a wood burning stove, in all likelihood you’ll have it on far more than to simply warm the place up. It’s something to do with that primeval cave-dwelling thing, or perhaps our love of just feeling cosy.
In summary then…
I think that wood burning stoves are a fantastic addition to any house. Not only do they look lovely burning away in the corner, but they can also save you money and reduce on your carbon footprint. They may not be as user friendly as simply turning on the central heating and adjusting the thermostat, but on the flip side owning a wood burner allows you to take a chunk out of the energy bill for said central heating, turn it on a little later in the year and even turn it off in some rooms. Additionally you can heat your home using use a renewable resource that is also often a waste product as well. Happy burning.
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