Brændefyrings bidrag til luftforurening - DCE - Nationalt Center for ...

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that it cannot readily be assumed to be valid for Denmark in general. It
should further be noted that the official emission factors are updated annually,
resulting in a decrease in the official aggregated emission factor
from 672 g/GJ in 2005 to 533 g/GJ in 2008.
In a chapter on emission factors, a potential pitfall is pointed out: There
is a dramatic difference between emission factors based on measurements
which include condensable particles (such as the Norwegian standard
NS 3058-2), and emission factors based on measurements which
neglect condensable particles (such as the German standard VDI 2066).
The difference is modest if a stove is operated under completely ideal
conditions, whereas the difference is a factor 2-10 for a stove in realistic
operating conditions. Emission factors accounting for condensable particles
– as those commonly used in Denmark – are the most relevant as an
indicator of outdoor air pollution.
Finally, interesting results have emerged from a limited study of indoor
pollution, where focus was on soot in indoor air. In a house with a wood
stove, the stove can contribute considerably to indoor pollution. In a case
study, bursts of pollution were observed to be emitted each time a cold
stove was lit. Poor draft had the result that pollution was dispersed into
the living area instead of being emitted through the stack.