Never exceed the recommended maximum load. Doing so may result in damage to the fireplace which will shorten its usable life span or may even damage it beyond repair.

It is relatively easy to work out how much wood should be burnt in a specific kilowatt close combustion fireplace.

Wood has a potential calorific value of about 5kW. Use this and subtract the moisture content of the wood being burnt to get the calorific potential of your wood.

e.g. 5kW – 20% = 4.8kW

If you have a wood stove that is rated as 10kW then to calculate the maximum kilogram per hour consumption rate by dividing this by your wood value.

e.g. 10kW ÷ 4.8kW = 2.08 kg of wood per hour.

Fireplace Calculator

Step 1: Calculate potential

5kW – moisture content % = wood potential output


Step 2: Calculate wood per hour 

10kW (stove max output) ÷ wood potential output

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