Stove Kilowatt Output

When choosing your wood burning stove or multi-fuel burning stove the most important thing to consider is the kilowatt (kW) heat output you need for the room the stove will be in. The information in the sections below should help you to understand more about the required kW output and what can impact it.

A Stoves Heat Output

A stoves heat output is measured in Kilowatts (kW) and the higher the kW the greater the heat output. It is essential that the kilowatt output of the stove you choose is appropriate for the room size that the stove is sat in.

If you have a stove that generates more kWs of heat than your room needs you could be too hot when the stove is working at its normal operating efficiency. The simple solution is to run the stove with less fuel and with all vents closed, reducing the air flow into the stove thereby reducing the heat produced. This is not a good use of the stove as burning a stove under its designed output can result in incomplete combustion of your fuel resulting in more soot and tarry deposits which create a greater risk of chimney fires. You could open a window or door to let some cool air in, but this kind of defeats the object of having a stove!.

On the flip side, if your stoves kW heat output is too low for your room then it will not heat the room up fully and you may find you need the central heating on to back up the stove, again not a great situation. If you try to compensate for this by running the stove extra hot by opening all vents and packing the stove with fuel, i.e. hotter that its normal operating efficiency as stated by the manufacturer, you could damage the stove and the flue liner.

Remember – if you choose a stove with a greater than 5kW output, i.e. 6kW and up, you may need additional ventilation in your room, e.g. an air brick if there isn’t already one. See our Stove Ventilation page for more info.

Kilowatt Output Calculator

Calculating the size of stove you need is fairly scientific but not 100% accurate as there are lots of things that can influence the results. In a house with average insulation, to maintain a 20℃ room temperature when it’s around 0℃ outside, you need approx. 1 kW of heat output for every 14 cubic metres of space in the room. So multiplying the height of the room by the width by the length (all in metres) gives you the room size in cubic meters and divide this by 14 and you have the kW heat output that you need. But what exactly does ‘a house with average insulation’ mean…?

Use the calculator to establish the kW output you need to heat your room.

Remember:The kW output you need to heat a room can be affected by things like:

  • Are the windows in the room super insulated or super drafty, double glazed or single glazed?
  • Are there any doors in the room that lead to the outside world and are they drafty?
  • Are there doorways leading to other rooms with no actual doors in them, so heat is being shared with other rooms?
  • Is there an open staircase in the room for heat to escape through?
  • Are any of the walls outside walls and if so are they insulated in some way?

So you may wish to select a stove with a slightly larger or slightly smaller kW output dependent on the type of room and how well insulated it is. If you are still not sure, when you arrange a site survey with your installer, they can make recommendations based on their knowledge and experience.

The Physical Size of a Stove

Don’t be fooled by the physical size of a stove – there is no rule that says the bigger the stove, the bigger the heat output. The size of a stove is determined by its design, what it’s made of, what fuel it can burn… etc. Some small stoves have a bigger kW heat output than some bigger stoves.

The physical size is important when it comes to the position of the stove, i.e. where exactly it will sit in your room. If its free standing, i.e. not in a recess or chimney breast and not near any combustible materials then you should have no clearance issue. The stove manufacturer will specify the minimum amount of clearance required from combustible materials.

If it is in a recess then the stove will need adequate clearance around it, i.e. space to the top, back and sides to allow air to flow around it. This ensures the heat gets to the room and is not wasted just heating up brick walls. More about the position of your stove can be found on our Stove Position page.

Keeping Your Stove Safe & In Good Working Order

Whichever stove you choose and whichever fuel you burn your stove needs regular sweeping and for this you will need a professional and experienced chimney sweep. That’s where we come in. Each stove manufacturer makes recommendations for sweeping frequency and East Sussex Fire Service recommend the following sweeping frequency based on the type of fuel used:

  • Smokeless fuels – at least once a year
  • Bitumous coal (ordinary house coal) – at least twice a year
  • Wood – quarterly when in use
  • Oil – once a year
  • Gas – once a year

We recommend sweeping at least once a year, before you start using your stove to remove any soot and debris that has built up inside the chimney and to make sure it is not blocked. If you use your stove regularly, have it swept regularly.

To Book A Professional Chimney Sweep In Brighton & Hove, Get In Touch Today To book a chimney sweep appointment, call us on 01273 726 989 or 07742 829 848. Alternatively you can book online using our simple Online Booking Tool. It is quick and easy to use, you can select the date and time that suits you and pay securely with a debit or credit card via PayPal. Stay safe when using your fire or stove, keep your chimney clean!