To achieve a relaxing room temperature of around 21ºC when the external air temperature is at freezing (0ºC) you will need approximately 1kW of heat output for every 14 cubic meters of space
To do the calculation yourself you will need to open the calculator on your phone and start by measuring the length, width and height of your room and then multiply the three figures together.
So for example, a room measuring 7m long by 4m wide and with a height of 2.5m is 70 cubic metres divide this figure by 14 and the answer will be 5, meaning you will require a 5kW stove to heat your home.
Remember this is just a rough guide, factors such as the number of outside walls, the size of windows and whether they are double glazed, what year the home was built, can all influence the heat requirement needed.
When buying a stove you will be looking at the kW rating but, some will have a nominal heat output and others will offer a range, so depending on what you are looking for you should be able to find a stove that will heat up your home pretty well, as a general rule the more you put in a log burner the hotter it will become so a small 5kw might not get as hot as large 5kw if overfilled with wood.
I would, however, recommend getting a stove pipe thermometer to ensure you’re not over burning or underburning, ensuring that you’re getting maximum efficiency from your stove.Often the stove will have an efficiency rating; this is basically the heat which doesn’t go up the chimney. The new Ecodesign ready stoves are all over 80% efficiency compare this to an open fire at around 28% efficiency or a stove produced a decade ago, with an average efficiency of 65%. The energy efficient improvements under the new Ecodesign ready scheme are game-changing.
Don’t forget about central heating, if you’re going to have this on all the time and then the stove is not going to be your primary heat source, then you might not need the full kilowattage you have just worked out. So be realistic, having a large stove might seem like a great idea but remember anything over 5kw will need an air vent perhaps not a problem but I know from experience it’s not something that most homeowners want, a draft wasn’t specified in the brochure right!