ompressed logs , also called compacted or densified wood, are a 100% natural high-efficiency fuel, which guarantees optimal heating time. It is an excellent alternative, both ecological and economical, to traditional firewood. In this article, we explain everything about the compressed log, its advantages and its use



What is a compressed log?

The compressed log is simply a log made from wood residue. You may also find it called compacted wood or densified wood, but it is exactly the same thing.

It is generally obtained from untreated sawdust or shavings, recovered from wood industries. This wood waste will be crushed, dried then compacted to finally take the form of a compressed log of wood using a briquette machine. It is the natural binder of wood, called lignin, which contributes to compression. The compressed log is therefore a natural element that does not contain toxic chemicals. Most often, beech, oak and pine residues are used.

The logs can take several shapes: cylindrical, rectangular or even cobblestone.

This heating fuel is used in the same way as conventional wood logs, but it offers a much higher calorific value.

What are the different types of compressed logs that can be found?

There are two types of compressed logs  :

  • The compressed log of the day: we use the heart of the wood and very little, if at all, bark. It contains a certain proportion of resinous trees, its combustion is shorter (around 2 hours) but it gives off more intense heat.
  • The compressed night log: it consists of a little sawdust and compressed wood bark. This log offers slower combustion (around 6 hours) and will create a layer of hot embers in the stove, to heat the room all night long.

The compressed day log is used to replace a classic wooden log. For the night time, it's a little different because you have to use less. Its objective is to keep embers, which will prevent you from restarting the fire from scratch in the early morning.

What are the advantages of compressed logs?

Densified logs have many advantages over traditional wood logs.

  • They are less bulky and therefore easier to store throughout the winter;
  • It is an ecological fuel made from leftover sawdust and shavings, which will be crushed, compacted and dried. The production of logs is therefore 100% natural and allows the wood to be given a second life;
  • Its calorific value is 3 times more efficient than that of a classic log. In fact, compression allows the wood to remain perfectly dry during storage, with a humidity level of 10% compared to 30% for conventional logs. It therefore produces more heat and burns more slowly;
  • They offer homogeneous and constant combustion;
  • They cannot be invaded by insects and pests because compacting the wood prevents moisture from entering. The quality of the wood is thus preserved;
  • Compacted wood produces very little smoke and ash, which allows your insert to stay clean longer and clog less;
  • Even if the starting price is higher, compressed logs are economical since the performance is better and they are used in smaller quantities.

Which devices are compatible with densified logs?

They can be used in all heating appliances designed for traditional wood logs: wood stoves, closed hearths or inserts, open hearths or classic fireplaces. It is even possible to use them in wood boilers and even better: in pizza ovens!

How to use a compressed log?

Lighting a fire with a compressed log is not difficult, just follow these different steps :

  • Place small balls of paper, or simply crumpled paper, in the hearth as well as dry kindling or pieces of crates;
  • Take a compressed log and cut it into small pieces before placing it at the bottom of the fireplace;
  • Light the paper on fire and wait until the kindling begins to ignite. Once the chips are burning well, wait for them to burn: the bed of embers is now ready.
  • You can now place a whole compressed log of wood in the fireplace;
  • Be sure to replace a new log every 2 hours maximum, so that the fire does not die. For night logs, just one will be enough for 6 to 8 hours.

It is important to only put one log in the appliance at a time, as compressed sawdust expands during combustion. For combustion to last as long as possible, you must avoid air inlets and never completely empty the ashtray which will regulate combustion.

It is entirely possible to mix classic logs and densified wood logs.

How to store compressed wood logs?

compressed wood logs must be stored away from humidity to maintain their properties. When purchased, they are protected by a plastic film which constitutes a first barrier against humidity. It is then best to store them in a garage or storeroom.