How does heating with pellets work?
Wood pellets are small pressed pellets in the shape of a cylinder and consist of dry, untreated residual wood (sawdust) that comes from the sawmill industry. They have a length of approx. 3.15 to 40 mm and a diameter of approx. 6 mm. The chips are pressed into their shape by means of high pressure and without chemical binders. This and the lignin contained in the wood bind the pellets together.
Once the pellets have landed in a heating system, they are automatically transported from the storage containers to the combustion system via transport screws or with a fan. A control system optimises the quantity feed and controls the combustion by means of a regulated air supply.
Danger of carbon monoxide poisoning in the pellet store
Because of their shape, pellets are delivered either in bags or even by tanker and then stored in fabric silos or underground tanks. And that is exactly where the danger lurks. Our two reports show how dangerous the odourless carbon monoxide (CO) can become in pellet storage.
Case 1 Carbon monoxide poisoning from pellets: death of a pregnant woman
In 2011, a 28-year-old Swiss woman died in a pellet storage room. Investigations revealed that the woman died from carbon monoxide emissions from the pellets.
Case 2 Carbon monoxide poisoning from pellets: Three employees poisoned
In January 2017, three municipal workers unknowingly came into contact with carbon monoxide at a heating plant in the canton of Vaud. One of the three already lost consciousness at the door to the pellet storage room. He was saved by his colleagues at the last second.
It is often known that carbon monoxide (CO) can be produced during the combustion of pellets in systems that do not function optimally. However, it is neglected that carbon monoxide also exists during the storage of pellets. The reason for this is chemical processes that are set in motion in the pellets and are strongly favoured by closed rooms. If the corresponding storage room for the pellets is not sufficiently ventilated, the gas accumulates. For people who enter the pellet store, the carbon monoxide then becomes their undoing. According to the Federal Statistical Office, more than 600 people die of CO poisoning in Germany every year.
Signs of carbon monoxide poisoning from pellets
If the dangerous respiratory poison CO is inhaled, it reaches the entire bloodstream via the lungs. Here it attaches to the haemoglobin of the red blood cells, exactly where oxygen (O₂) normally attaches. As a result, the red blood cells can no longer absorb and transport enough oxygen. The oxygen content in the body drops rapidly. Organs are no longer supplied sufficiently. The body collapses. As a result, carbon monoxide poisoning can lead to death within a short time.
Particularly problematic: The toxic CO is invisible, has no taste and cannot be felt. In addition, there are the rather unspecific symptoms as well as signs of carbon monoxide poisoning. After all, drowsiness, nausea, headaches or dizziness also indicate more harmless causes such as a lack of water. In addition to these effects, carbon monoxide poisoning also manifests itself in cardiac arrhythmia, dizziness as well as shortness of breath. The imminent danger becomes clearer in the case of unconsciousness.
How to prevent carbon monoxide poisoning from pellets
With the air-Q, the powerful and intelligent measuring device for indoor air quality, you can protect yourself from carbon monoxide poisoning. For this purpose, the air meter reliably checks the air components in your pellet store in real time and warns you when limit values are reached. Even if you are not at home, you will receive all important data and warnings via our air-Q app. This way, you'll know as soon as things get dicey, even when you're on the move.
(Cover photo: Shutterstock / Antonio Gravante)
