Have you ever looked at your wood stove and wondered how it works?
Below we’ll look at the science behind how a wood stove works, and most importantly how it can help to heat a room – or even a whole house.
The short version is that wood burns, after being set alight, in a classic wood burner stove and oxygen (a vital ingredient in any fire) is controlled by air vents included within the stove design.
Because waste gasses, created by the burning of wood, cannot escape, like with an open fire, they are held inside and generate more heat. All of this heat is radiated into the room via the cast iron stove and flue.
Table of Contents
How a Wood Stove Works
Now that we know the basics, let’s look at the specifics of how a wood burner works, what it actually does and why it has remained a firm favourite in the home heating world for over a century.
Wood Stoves Control the Heat
One of the main benefits of using a wood burning stove rather than an open fire is that wood is burnt more efficiently.
A good wood stove can have an efficiency rating of 80%+. This means that 80% of the energy in your wooden logs turns into heat for the room. Good news for anyone trying to reduce their energy use, and maximise energy output from fire.
Compare this to an approximate 20% efficiency in an open fire, and it becomes clear why a stove is a worthwhile investment.
The enclosed environment of the stove enables you to have a more controlled burn. Because the air vents are closable, you can decide how much oxygen your fire gets.
With an open fire, your fire has an almost unlimited supply of oxygen, meaning that it will burn through the wood much quicker. But, in the enclosed space, you can limit the oxygen supply to make the fire burn for longer at a more controlled rate.
The more open the air vents are, the more oxygen will get into the fire, and the quicker it will use up all the energy stored within the wood. This may give you a lot of heat for a short period, but it’s unlikely to last as long as a wood burning stove.
Wood Stoves Generate More Heat
Another way in which a wood stove works differently to normal fire is that it does not allow waste gasses to escape.
You probably think of smoke billowing into the air when you picture an outdoor campfire or your memories of summer camp. Although this might look nice, it’s not the most efficient use of a fire. When it disappears into the air, it stops being useful.
However if you inspect your wood burner in more detail (when safe to do so), you’ll see a baffle plate at the top of the stove. This panel with small holes allows some gas to escape via the chimney and some oxygen to come in. Whilst it regulates this in-out process, it also prevents the majority of gas escaping in one go.
Because this waste gas cannot leave, it stays in the stove and gets hotter.
Of course, some waste leaves via the flue but nowhere near as much as is lost into the air with an open fire or fire pit.
The most common of these waste gasses is carbon dioxide. Every 1000g of wood you burn releases 1900g of carbon dioxide.
The only way for air to enter is via the stoves air vents, and the only way for it to leave is via the flue. This prevents oxygen from enabling the wood to burn too quickly and stops waste gas from going before providing a sufficient amount of heat.
Wood Stoves Radiate Heat
Now we’ve covered how the wood stove gets hot, it begs the question, how does this heat radiate into the rest of the room?
That is where the outside of the stove comes into play.
Have you ever noticed how almost all stoves, from fancy modern designs to those created decades or even centuries ago, are all black and made of metal?
The color black and metal have a key commonality: they are both excellent radiators of heat. They absorb the heat from the stove and radiate it out into the room.
You can help this heat radiate more efficiently by putting the stove on the bottom floor in the middle of the house, when possible. You can also install vents throughout the house if you want the heat to move and spread into other rooms.
How to Increase the Efficiency of your Wood Stove.
All of the above explains the working mechanisms of a typical wood burning stove, but you can always help make your wood stove even more efficient by following these tips.
1. Keep it clean
If less heat is absorbed by the dirt and muck, more heat can be transferred into the room. So be sure to keep your wood stove clean and tidy.
2. Use the right wood.
Any wood you use ought to be no more than 20% water. Wet wood is inefficient as your fire will need to evaporate the woods water content before it can properly burn through the wood and generate heat for the room.
3. Keep the stove door closed.
Some people believe that an open door is better because it allows more oxygen to enter. And whilst that will happen, the vast abundance of oxygen will let the wood burn too quickly much like an open fire.
4. Get it started correctly.
Use paper and kindling to get the fire started, but use larger logs to keep it going.
–
We hope this gives you a clearer idea of how a wood stove works, and what that actually means from a practical perspective.
For everything else home heating, stick with CosyWarmer.com