Wood is the oldest fuel. It enabled the discovery of fire, and allowed early humans to cook food, keep warm and defend themselves: in short, the survival of the human race is inextricably linked to wood. As it burns, it releases energy, essentially reversing the process of photosynthesis, when a plant’s chlorophyll absorbs energy from the sun to produce the nutrients needed to grow and thereby form the wood itself. Having somewhat fallen out of favour since the discovery of fossil fuels and especially coal, wood has made a comeback in recent years.
Its resurgence in popularity is due both to society’s growing environmental awareness and the rising cost of other fuels, most notably gas. In fact, international tensions have highlighted how critically we depend on fossil fuels and foreign energy suppliers.
Although wood was traditionally used in log fires, more recently it is also used in the form of pellets (pulverised and compressed into small cylinders) and wood chips (reduced to flakes). Wood is the focus of this article, which is about how to heat the home without gas.
Heating without gas
Wood is still widely used for heating, especially in rural areas near to woodland. In isolated places with no mains gas supply, it becomes an essential resource. It is also a valid energy source for those who live in large or dated and energy-inefficient homes. In many cases, wood heating supplements a primary heating system, whereas in other cases it is the main system for heating the home. Classic open fireplaces and traditional wood stoves are common, but both are inefficient and rather polluting. Also widespread are more modern appliances such as pellet or wood chip stoves and closed fireplaces. Generally speaking, if a boiler is at least 15 years old it is likely to be obsolete and not very efficient, and this rule of thumb extends to old log burners and stoves too, and even to open fireplaces (although this does not detract from their aesthetic charm).
Replacing your old stove or boiler with a high-efficiency home heating system will cut consumption of fuel—whether that be wood or something else—and consequently save you money. The latest generation stoves have very high efficiency, up to 80%. They also emit fewer pollutants and, in a broader sense, have less environmental impact. Added to this is the advantage of a warmer and more comfortable home. It will certainly be expensive to make the change, but it will pay for itself over time. However, even installing a very efficient heating system may not be enough if your home is losing a lot of heat. Making a house more energy-efficient requires more complex measures, such as insulating the external walls, roof and/or attic, or replacing the windows and doors.
But let’s return to the subject of wood. To heat a house not with gas, but using woody biomass—i.e. wood and wood waste that is not contaminated by glue, varnish and the like—you can use these high-efficiency systems:
Boiler fired by wood, pellets or wood chips: works as a heat generator for the home’s central heating system.
Stove fired by wood or pellets: heats the air in the room where it is installed, but can also heat neighbouring rooms by means of ducts. Some types of stove can be connected to the existing heating system, for example to radiators or underfloor heating.
Burner fuelled by wood or pellets: essentially a closed hearth fireplace enclosed by one or more glass surfaces, and which works like the stoves mentioned above.
Fireplace insert fuelled by wood or pellets: creates a closed combustion chamber in an old fireplace, making it more efficient without affecting its antique appeal.
Wood or pellet stove?
Despite the price increases of recent years, wood in all its forms remains the cheapest fuel and has a lower environmental impact than fossil fuels. Wood and, more generally, woody biomass are renewable energy sources. If burned correctly it produces limited emissions. What’s more, gathering it helps to restore the equilibrium of the forest ecosystem and is an integral part of maintaining the rural environment. You might prefer to use it if you have access to a cheap and easy supply of firewood or wood waste, such as if you live in the countryside, woodland or even near to a sawmill or joiner’s workshop.
Let's gets down to brass tacks: are pellets or wood better? Wood is cheaper—or even free if you can forage your own—and gives you an inimitable experience: the welcoming ambiance, the relaxing aroma and so on… On the other hand, it is a less efficient and dirtier fuel than pellets.
Is a wood stove better than a pellet stove? Compared with pellet stoves, wood-burning stoves are a little more restrictive: you have to load them by hand because they are not powered automatically, you can’t program them (on/off time, temperature, etc.), the technical requirements for installing them are more stringent (for example as regards the flue) and they take up more space (think of the wood pile, for example). However, the purchase and installation costs of a wood stove are lower than those of a pellet stove.
For high-performance biomass stoves, here in Italy you can take advantage of various incentives, specifically Superbonus, Ecobonus, and Home Bonus tax breaks, as well as subsidies from the less well-known Conto Termico support scheme for renewable heating, and related regional initiatives. There may be similar financial support available in your region or country.
How hot does a wood stove get?
How much wood is needed to heat a 100 m2 area? How many pellets are required for the same area? The Italian Agroforestry Energy Association (AIEL) has calculated the equivalent energy output of different types of biomass. To heat a moderately insulated 60m2 apartment for one year would require 10 MWh of energy, corresponding to approximately 2,500 kg of seasoned wood or 2,000 kg of pellets. To produce the same amount of energy from fossil fuels, you would have to buy 1,000 litres of diesel or 1,000 m3 of methane.
Whether you opt for a wood or pellet stove, the important thing is not to be tempted to install it yourself. You need to seek advice from a heating engineer, who will help you to select a suitably sized high-efficiency appliance for your home. When choosing a stove, you should take into account your locality, the size of the area to be heated and the characteristics of your home (including the quality of thermal insulation), whether it meets the installation requirements, and the space required. How you use it depends on your needs: will it be your sole heating source, or will it supplement an existing heating system? Will you use it to also heat a boiler, or in combination with a solar panel heating system? After that, consider your preferences, for example depending on how practical a stove is and the availability of local fuel. In any case, opt for the latest generation biomass stoves or boilers, which are certified according to UNI EN European technical product standards.
One of the advantages of heating a house without gas is precisely the absence of gas, which is potentially explosive. Also on the topic of safety, it is important that the wood or pellet stove is installed by a qualified professional with up-to-date expertise on systems powered by renewable energy sources. Equally essential for safety are periodic maintenance and cleaning of the flue or chimney by qualified and specialised technicians. Proper maintenance results in more efficiency and less pollution. Besides, if you’ve had a biomass boiler installed, maintenance is mandatory by law, and here in Italy, the same applies to all boilers.
Buy wood or collect your own?
Where will you get your fuel supply for your wood or pellet stove? You can gather it yourself from nearby woodland: to avoid incurring a fine, first read up on local regulations governing where, when and how you can cut wood for your own consumption. If you own agricultural land, a vineyard or orchard etc., use waste from pruning and various other tasks carried out on the land. In the same way, you can use wood left over from clearing embankments and ditches, as well as that obtained from tending plants in your garden. To easily transport the material from the woods and countryside you can use a tracked transporter.
Make sure you have the right equipment for the job: a pruning chainsaw or multipurpose chainsaw for seasonal cutting, or a brushcutter equipped with high-performance cutting line, blade or disk for clearing tasks. If you are looking for an overview of all the various pruning tools, read our guide to pruning tools.
Wood should only be burned after it has been adequately seasoned: this is because moisture reduces its calorific value. You can find our suggestions for seasoning in this article on cutting firewood. A chainsaw is also essential in this process, to chop the wood down to an optimal size for stacking it to dry out, as well as for loading it into the stove. Wood chips also need to be seasoned. They can then be burned as they are (if your boiler or stove is designed for wood chips) or used as a raw material for producing pellets at home.
As an alternative to making your own, you can purchase high-quality wood and pellets from a trusted retailer. To be sure of buying a good product from a yield and sustainability perspective, the key is to choose certified wood and pellets.
Wood is not the only option for heating without gas. Electricity is one alternative that you can use, for example to power a high-efficiency heat pump, which will provide heat in winter, cool air in summer and also hot water all year round. It is a solution that should be evaluated on a case-by-case basis. Although it will drive up your electricity bills, you can limit the impact by investing in a solar panel system.