Choosing the Right Heat Output for your Wood-Burning Stove

The heat output of any stove you’re looking at will usually be featured in its name or prominently somewhere in its description. It is the figure followed by ‘kW’. What that tells you is the nominal amount of kilowatts of heat that each stove is capable of pumping into your room. Obviously, for all the importance of the design and functionality of your stove, the amount of heat it will provide is going to be a key aspect in your decision-making process when you are choosing a stove.

How is the heat output measured?

It’s not an exact science, but the output is measured by seeing how much heat is generated on average over the course of a refuelling period specified by the manufacturer. In effect, the manufacturer has already specified the output they believe their stove is capable of achieving. Tests are carried out to make sure this is accurate. Of course, this can vary considerably depending on the amount and size of fuel you use, how frequently you decide to reload the stove and a host of other factors. The way in which the output is measured is the same for both wood-burning and multi-fuel stoves, so the resulting figure in kilowatts by either is comparable across different types of stoves.

Calculate the size of stove you need

What kW output do you need?

That very much depends on the size and type of room that you’re hoping to heat. Our  heat output calculator will give you a good idea of the approximate output you need from a stove based on the size of your room. If you know that the room is particularly draughty, is poorly insulated or has thin walls, you might consider adjusting the output accordingly. Likewise, if you’re not intending to use the stove as your main source of heating in the room, you might not need such a high output.

Don’t underestimate the amount of heat you need

You certainly don’t want to be rounding down your suggested heat output. If you’re buying a stove, it makes sense to buy one that heats the room effectively. Settling for a smaller stove than the heat output you really need on the basis of price is also counter-productive. A larger stove will soon pay for the price difference in the model by reducing your central heating bills.

Equally, don’t overestimate

But it’s not just a case of the bigger the better.  It is possible to buy a stove with a heat output that is too great for your needs, and that creates its own problems. The most obvious one is that the room will overheat, leaving you with a stove blazing and windows open as you battle to control the temperature.

The other main problem with installing a stove that is too big also hits you in the pocket and affects the environment too. If the stove gives off too much heat for your room, it is inevitable that you will be attempting to run the stove below its capacity to avoid the room getting too warm. This sort of smouldering fire allows gases to go straight up the chimney without burning. This pollutes the air and wastes your fuel.

While there will never be precise uniformity of heat output measurements across different stove manufacturers, it is in every manufacturer’s interests to strive for accuracy when they declare a heat output for a new model.

Having lots of disgruntled customers in cold homes is not really a sustainable position for any stove company to find itself in for any great length of time.