There’s nothing quite like warming yourself in front of the fire on a cold day, but open fires allow up to 90 per cent of the heat produced to be lost up the chimney. ‘The main reason for choosing a wood burning or multi-fuel stove, apart from aesthetics, is efficiency,’ says Nick Sloane, MD of Jotul UK.
‘They use heat more efficiently and more safely than an open fire. There are wide variety of stoves available nowadays, from wood-burning and gas, through to multi-fuel options, and, as well as heating rooms, some can also heat water or a limited number of radiators.’
How much will a stove cost?
At a push, you could buy a stove for a couple of hundred pounds, but don’t be surprised if it’s inefficient and poorly made. Expect to pay anything upwards of £500 for a good-quality 5kW design.
The real cost, however, comes with installation, which could set you back almost as much as the stove and varies depending on the professional.
If you opt to install your stove and flue on a DIY basis, you’ll need to notify your local building control department. But the simplest (and safest) route is to hire someone belonging to a body such as HETAS, who will self-certify the installation. They’ll also be able to deal with the building regulations for you – which cover everything from hearth thickness to flue height and ventilation.
Stove safety checklist
- Always use the right fuel for your appliance – as recommended by the manufacturer or search the HETAS website to find a fuel
- Keep all combustibles, including logs, at a safe distance from the hot stove
- Make sure any external air ventilation grills are not blocked
- Do not slow or slumber burn for long periods
- Never leave an open fire unattended without a spark guard
- Always use a securely-fitted fireguard when children are in the house
- Get your stove serviced annually by a HETAS Registered Installer
- To find your nearest HETAS approved retailer, visit: http://www.hetas.co.uk/find-retailer/
Like a boiler, a stove’s heat output is measured in kW, and working out the required level is something to consider early on. Depending on your home’s insulation levels, a large W5xL5m room will need between 3–7kW of heat.
A good rule of thumb is to calculate the room size in cubic metres and divide the figure by 15 (based on average insulation levels). So, a room measuring W4xL5xH2.5m – 50m3 – would need 3-4kW of total heat output; you can subtract the output of any radiators from this figure. In most cases it’s best to get a HETAS engineer to perform a proper calculation and installation.
‘It’s important to visit a stove showroom and talk to a qualified dealer to ensure the stove you pick is proportionate to the area it is going to heat,’ adds Nick. ‘Buying stove that is too small will mean you’re disappointed as, even when it’s running at maximum capacity, it will not give the ambient heat you are looking for. Equally, buying a stove that is too large for the area is a false economy and can result in poor combustion.’
Which kind of fuel?
For wood-burners, hardwood logs are denser than softwood, so you’ll receive more kWh (kilowatt hour) per bag. The drier the wood, the more effectively it will burn, so the best option is to store as much wood as you can and dry it out over two to three years. Buy cheap bags of freshly cut logs (at around £50–70/m³) and then let it dry out to boost its output. Then, you’ll enjoy costs per kWh of around 2–3p – a fantastically cheap source of heat.
It’s also worth checking out briquettes to supplement your log usage. These are factory-produced, have a stable moisture content and give an output of around 4.8kWh/kg. In addition, briquettes are easier to handle and produce less ash than wood – try talu.co.uk.
If you live in a town or city, check to see if you’re within a smoke control area; you can find out by contacting your local authority. If you do find yourself in one, then you’ll only be able to burn DEFRA-approved smokeless fuels, such as anthracite. Alternatively, if you want to burn wood or non-exempt fuels, you’ll need to specify a DEFRA-exempt stove; there’s a list available at smokecontrol.defra.gov.uk, or you can ask suppliers for recommended models.
Many stoves are freestanding, allowing you chose where you want to position them to get the best view of the flames and, of course, the best heating,’ says Nick. ‘Stoves can be positioned against a wall, in an existing fireplace, or in the centre of a room flued through a ceiling.
There are also insert stoves, which can be flush fitted into a wall or dividing wall or even into an old fireplace opening.’ Finally, there are regulations on how close you can place a stove next to combustible materials and the type of flooring it can sit on. Your dealer or HETAS-registered installer will be able to advise.
Stoves with back boilers
For an alternative central heating solution, you can specify a stove with a back boiler, although this may not be the cheapest option. This combines a boiler function with the stove, to provide space heating and domestic hot water, as well as spot heating. These products, known also as boiler stoves, can typically provide between 5–20kW of water heating as well as the equivalent in output to the room. For instance, Charnwood’s Island IIB model (around £1,950) has
A HETAS-registered installer can advise you on how to link a boiler stove to your system, which will likely be by plumbing it into a hot water cylinder.
Stoves require an air supply for combustion to take place, so the air within the room needs to be replenished. In older, draughty homes, this doesn’t tend to be an issue. However, in modern, well-insulated homes, there may be limited airflow. Room-sealed stoves with a direct air supply (where the air is taken from outside the house) can be used in this instance.
‘One of the most important features to look at is “clean-burn”,’ adds Nick. ‘This means secondary combustion takes place in the firebox so, instead of burning fuel, you are burning the gases off the fuel, which leads to better efficiency and lower emissions. “Air-wash” is another feature to consider and is where cold air is preheated in the firebox and channels over the glass door to keep the glass clean.’
Chimneys and flues
A stove is often only as good as the chimney or flue to which it is connected. Existing chimneys will need to be investigated to establish whether they’re fit for purpose – they may need sweeping and should be lined. In homes without an existing chimney, there are a number of options available, such as introducing a stainless-steel twin-wall flue – these are particularly popular in open-plan and contemporary interiors.
‘We always recommend an annual flue/chimney clean to ensure no soot is left in the chimney and to prevent blockages, says Nick. ‘You should also do an annual inspection of your stove to check that the glass and seals are in tact and aren’t letting air escape. It’s also key to make sure you use the correct fuel for your particular stove and always operate it as per manufacturers’ instructions.’