What Size Log Burner Do I Need?

When you come to choose a wood burning stove, it can be difficult to know what size log burner is right for your home. Often, homeowners can mistakenly buy a stove that is far too large for their needs. Whilst it can be tempting to be “better safe than sorry” with a larger wood burner, it isn’t always the best option for you. Read on to learn how to calculate what size of log burner you need.

Things to Consider

A number of factors can influence which size of log burner is best for you.

  • How well-insulated your home is
  • How open the room is
  • How warm you like it inside
  • The fuel you use

All wood burning stoves are designed with a certain power output in mind. If a log burner is placed in the wrong conditions, it won’t run at maximum efficiency. This means higher fuel costs, more environmental damage from the exhaust, and improper heating. So choosing the right size log burner is vital.

Another thing to note is the size of the stove itself. To comply with Building Regulations, your stove will need a minimum of 150mm clearance to the sides and rear, as well as 225mm to the front of your hearth. For safety, you should also keep any combustible materials at least 950mm away.

How to Calculate Which Size of Wood Burning Stove is Right for You

Working out which size of wood burner you need is actually quite simple.

First, calculate the cubic meterage of your room by multiplying its width, height, and length. Then, divide this figure by 14 to get your ideal power output.

For example, in a room that's 6m x 6m, with a ceiling height of 2.5m:

6m x 6m x 2.5m = 90m3
90 ÷ 14 = 6.43

So for a 90m3 living room, you'd need a wood burner that was capable of 6.43 KW for adequate heating.

NB: For poorly insulated homes, divide by 10, and for new builds or homes that have been brought up to modern standards, divide by 25.

What is Power Output?

The power output of a wood burning stove is measured in kilowatts (KW). If your log burner is 5KW, this means that five kilowatts of heat are delivered into your room every hour.

Do be aware however, that the power output chosen by manufacturers isn’t always accurate. Stove manufacturers choose the KW output they’d like their stove to be rated at, and the stove is then tested for its efficiency at that specific output. This means that your stove could output a completely different level of heat depending upon ambient conditions, the fuel used, and more.

What is the Difference Between Nominal and Maximum Heat Output?

Two figures often given by wood burning stove manufacturers are the appliance’s Nominal Heat Output and Maximum Heat Output. Nominal output is based upon the heat delivered at the stove’s KW and efficiency ratings; however, this is often not the most heat you can get from your stove. In general, the maximum output figure is more reliable, and paints a more accurate picture of the heat you’ll get.

What Difference Does Fuel Make to Power Output?

There can be a significant difference in the amount of heat generated depending on the fuel you use. Well-seasoned logs should always be used, as any excess moisture needs to be burned off before heat is generated, and moisture can damage your stove. Hardwood often burns for longer, but this can vary depending on the exact type of wood.

If you’ve got a multifuel stove, you’ve got more flexibility in heat output. Man made and natural coals offer different properties and burn at different temperatures, allowing you to reach the KW you’d like to achieve. We’d always recommend coal for overnight burning.

In Closing

Once you’ve taken the time to decide what size of log burner is right for you, it’s time to take a look at some options! We’ve got a fantastic range of wood burning stoves, including freestanding wood burners and built-in wood burning stoves from leading brands such as Clearview Stoves, Dru Gas Fires, Spartherm, and more.