The limits for fumes from woodstoves and boilers
The most common reason that biomass is burned domestically is to heat spaces, for example using wood stoves, or to heat water in a biomass boiler.
Emissions regulations tend to be different depending on whether it is space or water which is being heated, although there are overlaps, for example in the case of stoves with back boilers.
In Europe, the minimum standard applying to solid fuel local space heaters with output up to 50 kW and solid fuel boilers with output up to 1 mW is the Ecodesign Directive (EN16510-1:2022). It sets limits for oxides of nitrogen, particulate matter, carbon monoxide and organic gaseous compounds.
However, the limits set in the Ecodesign Directive are widely regarded as being very unambitious and therefore some individual EU member states have decided to implement their own standards which are more demanding. For example, in Germany a regulation referred to as BlmSchV now applies.
As an alternative to regulations, some countries have introduced accreditation schemes to make consumers aware of the environmental performance of woodstoves. Examples of this include the Flammevert scheme in France and the Nordic Swan in Scandinavia.
There are increasing calls from air quality campaigners for wood stoves to be banned completely in cities so wood stove producers have realised that, regardless of regulations, unless they can produce much cleaner stoves, their future is in jeopardy.