Contrary to popular belief, wood fuel is one the most energy efficient home heating options out there. You just have to know how to get the most out of it and make a few right choices during the heating season.
The keys to efficient home heating are: a) the quality of the wood fuel you’re using, b) the material properties of that fuel, and c) the efficiency of your wood-burning appliance.
In this article, we’ll show you how to make your home heating more efficient and eco-friendly than ever before.
Wood Fuel Quality
Ask any expert and they’ll tell you that the most important determiner of wood fuel quality is its moisture content.
Poorly dried firewood burns inefficiently and releases a lot of smoke. This smoke contains a lot of compounds that are harmful to both human health and the environment. This includes creosote, which is both a cancerogenic substance and a chimenea fire hazard.
Dried wood, on the other hand, is a very efficient and clean heat source that produces virtually no smoke. What’s more, the more moisture you remove from a piece of firewood or a briquette, the more efficiently it starts to burn.
Defra’s Ready to Burn standard sets the standard at 20% maximum moisture, which is the amount where the law of diminishing returns starts to kick in in earnest (you need to put in a lot more effort per every % of moisture lost).
At Lekto, we cook our firewood and briquettes for a very long time in state-of-the-art industrial kilns. Thanks to this, our firewood contains an average of just 10%-12% moisture. And our briquettes and kindling are rated at below 9% moisture.
Wood Fuel Properties
The second key to efficient home heating is choosing the right kind of wood fuel. If you’re searching for the most efficient, energy-dense, and eco-friendly wood fuel possible, keep this simple idea in mind: Briquettes > Kiln-Dried Firewood > Seasoned Firewood > Poorly Seasoned Firewood.
Choose Briquettes Over Firewood
Briquettes are universally more eco-friendly and energy-dense than firewood. There are several reasons for this. First of all, briquettes are made from already-existing sawmill byproducts, so no trees are cut during their creation. Being porous, the byproduct materials they’re made up of can be dried to a much lower moisture level than can be achieved with firewood. After being dried, the sawdust is compacted to a very high density, which allows briquettes to contain as much as 4 times the energy of traditional firewood per unit of volume.
If You Have to Use Firewood, Choose the Kiln-Dried Variety
Can't use briquettes due to the limitations of your appliance or personal preference? Then choose kiln-dried logs.
As we discussed in-depth in our ultimate guide to firewood, kiln-dried logs are near-universally superior to the seasoned variety. They are easier to light, burn cleaner, can be safely stored indoors, and release much more heat than the seasoned variety. Their only drawback is the approximately 10%-15% price premium you'll have to pay for them.
If You Have to Use Seasoned Wood, Choose Ready to Burn Options
Unless you have been doing so for many years and have access to specialist moisture measuring equipment, we don't recommend buying unseasoned logs and seasoning them yourself.
When buying seasoned firewood, make sure it is certified as Ready to Burn. If the seller does not provide this information to you, steer clear of them and buy from someone else.
While it may seem like all wood burners burn wood the same, this couldn't be further from the truth. Modern wood stoves are much more efficient than those released as recently as twenty years ago. And, what’s more, we’re currently in the middle of yet another performance jump.
On 1 January 2021, the UK will adopt the Ecodesign standard, which regulates the amount of particulate matter a wood fuel-burning appliance can release into the atmosphere. When compared to earlier offerings, Ecodesign-certified stoves can release up to 4 times less particulate matter into the atmosphere.
Eco-design stoves are some of the most energy efficient home heating options out there. And while they do cost more than non-certified options (which will still be available for purchase in the near future), their increased efficiency makes them cheaper to use in the long run.