Simeon Brody
The weather's getting colder as we descend into winter. The central heating's being turned on, the electric blanket is being installed in the bed, or hot-water-bottles dug out of the airing cupboard. Some people are lucky enough to have a flue and hearth, and are lighting their open fires. Nice though the effect of an open fire is, they are incredibly inefficient.
They are, on average, just 15% efficient, wasting 85% of the available energy in the fuel as smoke (unburnt fuel) and the uncontrolled draught up the chimney. In addition, when the open fire isn't burning, the open flue is still sucking warm air out (from the other heating in the house) and if this is the case, the flue can be responsible for an overall negative thermal efficiency, as the chimney removes more heat than the occasional open fire produces.
The solution, well, one solution, is to replace your open fire with a stove. I have two woodstoves and when I describe them, people are often amazed that they are smokefree and that wood can be used in a smoke control area. Although not all stoves are designated smokefree, some are called 'cleanburning' and all are more efficient than an open fire. My two 'Clearview' stoves (built in Shropshire) have a patented system which preheats the air before it enters the firebox, which it does through many tiny holes, creating lots of turbulence and making it possible to completely burn all of the wood and get a thermal efficiency of more than 85%. And of course, logs are a renewable energy source, often given to me by grateful tree surgeons happy to dispose of their waste, or I'll collect from various places nearby with my cycle trailer.
Both my stoves have a flat top, which means that I can cook potatoes or pasta, boil a kettle, heat washing-up water and even bathwater using two massive 6 gallon saucepans. I also dry fruit on racks on top of the bathwater pans. They are pretty central to my eco-friendly life, and I enjoy managing the logpiles... cutting, splitting, stacking. Good healthy outdoor activities!
Having a good flue is vital. The flue is part of the system that some people seem to forget, and it should be smooth inside and not have kinks or bits jutting out. I had two insulated concrete liners put in, but it is possible to use a stainless steel liner or just the existing flue. Even with smokefree stoves, it is important to get then swept regularly as this increases the pull and reduces the chance of a destructive chimney fire.
If you are considering buying a stove, the smokefree versions are the most efficient and you get more heat from each log. Get a British-built model, there are several companies making them. ('Clearview Stoves' and 'Town and Country Stoves' are the two I know about, but there are others.) However, if you like your open fire and don't want to change, get a 'chimney balloon' which blocks the chimney whilst you aren't using it. This will save you lots on your other heating bills, but remember to remove it before you light the fire or your room will fill with smoke!
My solution when I became a home based worker and needed to work confidentially in a room in my large delapidated farmhouse which had previously had no heating, was to ask a local craftsperson to make me a stove from recycled materials (two gas bottles, a road sign (?) and a trowel handle to be precise. Not sure about the efficiency of my flue, but I am toasty warm!