Heat Logs:Are they any good?
What are they?
Heat logs or briquettes are a manufactured log designed to be burnt in stoves and open fires and are sold as an alternative to traditional fuels such as logs or fossil fuels.
What are Heat Logs made from?
Heat logs are made from sawdust, either virgin sawdust i.e. sawdust from freshly felled timber or from waste/recycled timber left over from manufacturing processes. They can and often are a mixture of the two. Increasingly heat logs are being imported and such imports can be made up of diverse materials ranging from corn husks to ground up coconut shells.
How are Heat logs made?
There are two types of heat logs – namely pressed and extruded. Pressed briquettes are solid, and tend to expand when burning. Some but by no means all, have a tendency to collapse into a pile of hot sawdust if poked or when more fuel is added on top. Extruded briquettes have a hole down the middle (left by the screw that extrudes them and not, as some have suggested “an added hole so they burn even better”!!), and form proper embers which will usually keep a stove hot all night without stoking up at bedtime or closing the air right down. They tend to have a much longer heating period.
The manufacturing process involved in both types should be of such an intensity to make the naturally occuring lignin in the wood to melt and flow so binding the sawdust particles together. The result should be a solid and dense heat log, preferably with a glazed appearance.
If your heat log crumbles easily then the manufacturing process has been skimped. Such logs will burn fiercely but for a much shorter duration and you will often find that many of the logs have crumbled into sawdust whilst still stored in the bag.
Are Heat logs the green alternative?
In as much as heat logs are manufactured from predominantly waste material which previously would have gone into landfill then yes, they can be described as green.
A well made heatlog will have a very low moisture content, often around 10% but can be as low as 6%. As a result they burn very efficiently with only minmal smoke, tar or soot so are less polluting than more traditional fuels especially house coal. An added bonus is that well made heat logs when burnt have a very small ash residue.
Be aware that many brands of heat logs are now imported, usually from Eastern Europe and Russia but increasingly from the middle and far East. It’s difficult to concieve a product as environmentally friendly when its travelled over 2000 kilometres or more to reach the UK even if it’s an efficient fuel!
It’s also worth bearing in mind that the very waste product these logs are made from has become a valuable commodity in it’s own right and as a result some manufacturers are beginning to “experiment” with alternative waste materials.
They are clean and easy to handle and store and can be be an attractive alternative fuel to consumers who don’t wish to deal with large amounts of traditional firewood logs.
Is there a manufacturing standard?
The short answer is no. Some heat logs currently being offered for sale are woeful. We’ve tried just about every brand on the market and there are very few which come up to expectations. The more reputable UK manufacturers voluntarily subject their products to scrutiny by HETAS, the Government’s solid fuel advisory body and if successful are awarded “Woodsure Plus” accreditation. The brand we offer for sale, UK Heatlogs, are one of the few to have achieved this accreditation.
Do Heat Logs work?
A well made, dense, solid and heavy heat log, preferably manufactured in the UK and bearing the “WoodsurePlus” accreditation should, all things being equal, out perform even the very best kiln dried logs and come very close to fossil fuels in terms of heat output with only a fraction of the green house gas emissions.
To get the most from these fuels it is worth experimenting with your stove as each one has its own unique personality and characteristics which can fluctuate even with weather conditions.
As a general guideline we burn these in the following way on our 8kw Hunter Herald stove:
A single heat log is broken into “biscuits” with the aid of a small axe – each biscuit is around 25mm in thickness. These are piled around a firelighter and the stove is lit with all air controls fully open. After a few minutes when it’s obvious that the biscuits are burning well, a second whole log is added and the bottom air control closed off completely. After a few more minutes the top air control is closed until it’s open only a fraction. If the flames start to die down, open the top air control a fraction more. The idea is to achieve a good flame without all the heat being forced up the flue! Once the flames begin to die down then a further log is added to maintain the burn. If you’re using a multi fuel stove it’s important to make sure the fuel grate is totally closed. Burnt in this manner, 3 -4 logs should last an entire evening making them a very economical way to heat a room. UK Heatlogs are quite capable of running a back boiler stove used for radiators and providing hot water as several of our customers have discovered.
Here’s a link to a short video from the manufacturer illustrating another method…..nice music!
Border Biomass Fuels have trialled just about every brand of heat log on the market and chose UK Heatlogs to offer our customers which we found offered the best trade off in terms of cost and fuel efficiency. They’re dense, solid and heavy and bear the all important “Woodsure Plus” accreditation. We have no hesitation in recommending them. They are available in our online shop HERE for free delivery and of course free stacking. Too many? Why not try our Winter Special Offer – 20 boxes – 200kgs with free kindling!