Why does firewood pop

You may find that hotter burning fires can produce more popping and crackling noises because the wood can be combusted and gases created at a faster rate, giving more opportunity for these gases to get trapped and force their way out with a pop and crackle. Sufficient air supply is an important aspect of any fire and so ensure that you either have an air vent or window open in the room if your fires are struggling.

While fresh oxygen is required to keep your fires burning hot, waste gases also need to be removed from the fire at the same rate. For more information we have guide to improving the draft on your fireplace right here. Seasoned firewood is the perfect choice of firewood for hearing the most amount of pops and crackles from your fires.

Properly seasoned firewood will typically have retained enough moisture for steam to escape and produce popping and crackling sounds. At this moisture level firewood is dry enough to catch fire and burn without any issues, but also not too dry that it would burn too quickly to be an efficient source of heat.

This amount of moisture in seasoned firewood helps to keep the logs burning for a reasonable amount of time, but it also enough moisture retained that it can provide a greater opportunity for the firewood to produce pops and crackles. To reduce the amount of pops and crackles from your fires look to burn kiln dried firewood that is very low in moisture content.

The typically reduced amount of moisture within kiln dried wood compared to seasoned firewood can lead to more infrequent popping and crackling noises from fires. Due to the humidity of the atmosphere kiln dried firewood can be able to reach lower moisture content levels compared to when seasoning firewood outside through air drying. Firewood can only be seasoned down to a certain moisture level depending on the humidity of the air around it.

The higher the moisture level of firewood, the more pop and crackle noises can be produced as the excess water tries to escape. Some types of wood popping and crackling more than others can be as a result of the difference in moisture and sap content. Seasoned softwood logs have the potential to produce more pops compared to kiln dried hardwood logs because of higher moisture and sap levels.

Wood with higher sap content, such as softwood logs, can act much like trapped moisture escaping the wood and making the traditional fireplace sounds. Firewood with the right amount of moisture and higher in sap content will be able to produce more of your favorite fireplaces sounds. A Guide To Seasoned Firewood. In the same way water in a kettle heats up and turns into steam, so does the water trapped inside the log.

So as the fire gets hotter, the water and sap inside start to boil and turn into gas. As the fire gets even hotter, these gases start to take up more space and expand get bigger.

While the water and sap turn into steam, something also happens to the wood. Wood contains something called cellulose, which is the stuff that plants are mostly made out of. When something in nature like a piece of fruit decomposes, it changes. Read more: Curious Kids: when I swipe a matchstick how does it make fire? When wood in a fire gets hot enough, the cellulose inside starts to turn into gas. This is when we see smoke coming out of the wood, sometimes even before that piece of wood has burst into flames.

The flames happen when the gas escaping from the wood starts to mix with the oxygen in the air. Oxygen is like food for fires — it makes them burn really bright. As wood burns, the mix of expanding gases and cellulose breaking down makes the pockets of trapped steam burst open from the wood, one by one.

Rapidly expanding gases inside the pores of the burning material are responsible. The crackling sound from wood fires comes from the sudden escape of combustion gases from pores in the wood. The chemical reaction that occurs when wood is burning is an oxidation reaction. Wood is composed of cellulose, which is a polymer made up of chains of glucose C 6 H 12 O 6 molecules.

When it combines with oxygen from the air, the exothermic reaction releases carbon dioxide and water vapor, as well as energy in the form of heat and light. The chemical equation for wood combustion is:. During this process, the wood isn't burning.

The wood is sublimating changing state from solid to gas , and the gases produce the flames. If the temperature isn't high enough to ignite the gases, they dissipate — together with unburnt wood particles — as smoke. Wood isn't as solid as it looks. It's filled with microscopic cells with walls made of cellulose, which is the substance that sublimates during combustion. As the cellulose changes state and releases gas, the gas is trapped in the pores between cells.