What is overfiring a wood-burning stove?

flatmate_room

If you’ve been reading up on operating a wood-burning stove, you might have seen people advising you to avoid overfiring. So, what is overfiring?

Overfiring is essentially the process of operating your stove at too high a temperature. Woodburners are supposed to operate at high temperatures, but there are optimum temperature levels and going above them can result in damage being caused to your stove. In particular, the stove body and the internal parts are susceptible to becoming warped if your woodburner is being overfired.

What causes overfiring in a wood-burning stove?

To overfire your woodburner, you must be operating it incorrectly. In other words, something you are doing is causing the stove to burn hotter than it has been designed to burn, so the prime suspects are:

Too much oxygen

Allowing too much oxygen into your firebox can result in overfiring. For instance, leaving the door open, having the vents open too wide or operating the stove with faulty stove rope in place could all result in too much oxygen getting to the fames.

Too much fuel

Another possibility is that too much fuel is being added to your stove. This might result in a fire that is too intense and therefore cause damaged to the appliance.

Avoiding overfiring with your woodburner

The easiest way to ensure that you are not overfiring your wood-burning stove is to install a stove pipe thermometer. This will measure the temperature of gases leaving your woodburner and help your to ascertain whether your stove is being operated within its optimum levels or if you are overfiring it.

Equally, it will show you if the stove is not being operated at a high enough temperature, which results in an efficient and environmentally unfriendly burn, fuel being wasted and creosote build-up in your chimney.

Click here to buy a stove pipe thermometer.

Great European woodburners

Flag_of_Europe.svg

This week the United Kingdom will go to the polls to decide whether to remain in the European Union or leave it. While we won’t get into the politics here, we will mark the occasion with a tour around Europe to see some of the woodburners manufactured in different EU counties that are available to buy from Gr8Fires.co.uk.

France: Invicta
France flag
French brand Invicta has built a reputation for eye-catching contemporary stove designs. The usual notions of what a woodburner should look like are frequently ripped up in favour of new and exciting looks. Invicta stoves tend to make brilliant feature pieces within the decor of a room, but that shouldn’t (and doesn’t) detract from its primary function of making your home cosier.
Invicta Chamane
Click here to see more Invicta stoves.

Slovakia: Thorma
Flag_of_Slovakia.svg
A lot of wood-burning stoves are either the traditional black boxes we’ve always had in the UK or Scandinavian-influenced freestanding stoves. One of the joys of the Thorma range is that it exposes some of the heritage of woodburners in eastern Europe. As such, the stove designs are often unusual and interesting.
felix
Click here to see more Thorma stoves.

United Kingdom: Arada
1200px-Flag_of_the_United_Kingdom.svg
And so back to the UK to complete our little tour. We stock several British stove brands, but we’ve picked out the Arada range to fly the flag on this occasion. Predominantly using high quality steel for its appliances, Arada offers a collection of sleek, minimal and modern woodburners.
ecb5plus-defra
Click here to see more Arada stoves.

Weighing logs: an experiment on the wood seasoning process

relative-mass-set-A

Our attention has been caught by a little experiment that promises to give an insight into the wood seasoning process.

As we regularly mention on this blog, it is important for the well-being of your woodburner and the efficiency of your fuel use that all logs are fully seasoned before burning them. The easiest way to check this is by buying a moisture meter to measure the water content in a log.

Robert Pumphrey has opted for a slightly more laborious process that continues to garner some interesting results. Rather than use a moisture meter, Robert has deployed his humble kitchen scales to regularly weigh a sample of logs. He is working to a hypothesis that when his logs stop losing mass, they will be ready to burn (because this will suggest that all or most of the moisture in the log has evaporated).

This approach is probably not manageable as a preferred method of checking your wood is seasoned, but it does provide some interesting data on the seasoning process.

Robert used just eight logs as a sample for the experiment. He took weekly measurements of the mass of each log, then recorded his results.

He quickly discovered just how much water a log holds and also learnt why we recommend seasoning logs outside under a covered but open-sided structure.

Summarising his observations to date, Robert said:

Logs contain a lot of water. If you have 100kg of fresh logs in your shed, that may be around 35 litres of water

 

When you fill a shed with fresh logs, you can expect a significant volume of water condensing on the roof. Perhaps it makes more sense to dry logs outside first if you have the space

 

Logs put on mass when the weather is not very warm, get your logs in the shed by April if you need to use them next winter

 

I want to keep tracking this set of logs to see if they lose a significant mass of water on their second summer in the shed.

You can see a graph of Robert’s findings to date above.

If weekly weigh-ins are not for you, you can use a moisture meter instead. We’ve previously calculated that using a moisture meter can save you up to £206.55 each time you burn a tonne of wood.