Emissions from wood and coal burning stoves in residential areas

different houses, covered with snow, with smoking chimneysClick to enlarge
Especially in the winter time the air can be contaminated with fine dust from chimneys and stoves
Source: Grzegorz Polak / Fotolia.com

Smoke from house chimneys can lead to unpleasant odours in the neighbourhood and be harmful to health.

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Use of wood and coal stoves in residential areas

For many people it has become attractive again to use stoves and fireplaces in addition to the central heating. For some it is the cosiness and warmth, and a higher living quality. For others heating with wood, coal or pellets is a cheaper alternative especially in the evenings of early spring or late autumn when the central heating is not in use.  

According to the Federal Association of Chimney Sweepers around 11.7 Mio so called “single-room firing systems” are installed in Germany. They also reported that the number of traditional coal stoves is decreasing, the number of modern wood and coal burning stoves and featured fireplaces is on the increase. The Federal Association of the Energy and Water Industry reported that 27% of German households have such stoves in addition to a central heating system. 
In order to counteract air pollution through improper use or technically outdated stoves and fireplaces the German Government took appropriate measures by stipulating in the revised 1st ordinance of the Federal Immission Control Act (1.BImSchV) the following:

  1. Only untreated wood (logs, wood shavings, pellets or briquettes) which has been stored for a certain period of time is permitted for combustion.
  2. In a defined step-by-step plan, outdated single-room firing systems are to be replaced.
  3. Open fireplaces may only be used occasionally.

Operators of single room firing systems must comply with the requirements given. Chimney sweepers check for compliance with the regulations.


The smell of “winter” can be harmful to health

Heating with wood, even if properly performed, causes significantly greater air polluting emissions than other fuels like oil or natural gas. Therefore, it cannot be ruled out that short-term pollution with fine dust and polycyclic aromatic hydrocarbons (PAH) might occur in some residential areas, especially under inversion weather conditions when a large number of wood burning stoves and fireplaces are in use and . Air emission measurements commissioned by the UBA showed that wood combustion exhaust gases are a significant source of fine dust pollution in residential areas.

Fine particulate matter is dangerous to humans, due to the smallness of the particles. The smaller the particles, the deeper they penetrate into the respiratory tract. The smallest particles (so-called ultra-fine particles) enter the blood circulation and are spread to all organs - even to the brain. Health effects that are related to fine dust exposure range from mucosal irritation/local inflammation of the bronchial tubes, increased plaque in blood vessels and also to stroke and cancer. The emitted dust particles can contain PAH from incomplete combustion. Some of these compounds are carcinogenic. A connection between neurological disorders such as dementia and Parkinson's disease is also discussed in the scientific literature.

Wood combustion emissions in residential areas can cause limit values exceeding concentrations of fine dust in outdoor air. The EU has set an annual mean limit value for PM10 of 40 µg/m3 and a 24h-limit value of 50 µg/m3 (not to be exceeded on more than 35 days a year). However, a WHO-report from 2013 (REVIHAAP) showed that these values could possibly be too high to protect health adequately and need to be reviewed. Currently in many of the EU countries including Germany the limit values for particulate matter are sometimes exceeded at certain measuring stations.


Our advice on wood burning systems

  1. Use your fireplace or wood stove only occasionally. Open fireplaces are very energy inefficient, cause very high uncontrollable emissions, pollute the indoor air significantly and pose a fire hazard. Even closed wood burning stoves should not be used regularly, emissions emitted can affect your health as well as the health of your neighbours
  2. When using a fireplace or stove always follow the manufacturer’s and chimney sweeps’ recommendations and only use suitable fuels, in particular, dry untreated wood. Not suitable and in general prohibited is the burning of painted or treated wood as well as plywood, chipboard or fiberboards. Also paper, cardboard, combustible waste and garbage must not be burnt.
  3. Use a wood moisture measuring instrument, they are inexpensive (often under 20 €) and available in most hardware stores. In order to avoid heavy smoke and ash, and a low energy yield, your wood should never contain more than 25% moisture. You might want to point this out to any neighbours using wood burning stoves.
  4. If you yourself feel annoyed or are angry with any of your neighbours, sometimes an honest discussion can be very helpful and often a solution can be found. If the source cannot be identified the local chimney sweep or local authorities are possibly the best institutions to contact.
  5. The burning of unsuitable fuels is no trivial offence, it is a health hazard to the entire neighbourhood and beyond. If you suspect or have evidence that someone in the neighbourhood is burning paper, cardboard, damp or treated wood, garden waste or pellets made from any of these raw materials then make the people responsible aware of the problem. If they choose to ignore your complaints then the local authorities or environmental agency are the institutions you might need to contact.