The tiled stove and the environment
In the last few years, public discussions have literally fueled the discourse regarding the influences of the tiled stove on the environment and, in particular, on the particulate emissions of wood-fired heating. The media were increasingly talking about two major emitters – the traffic and biomass heating systems. Some of it has to be clarified and put right in the course of this dialogue.
Definition of terms and health hazards
Fine particulates are basically part of the total airborne dust TSP which is composed of differently large air particles. The term PM 10 is often used in context with fine particulates. PM 10 is a mixture of solid and liquid particles and air with an aerodynamic equivalent diameter of <10µm. Potential hazard are strongly depending on the size of the air particles. The categorization is performed as follows: coarse dust (>10µm), inhalable fine dust (<10µm), respirable fine dust (<2.5µm) and ultra-fine particles (<0.1µm). Particles which are referred to as respirable or ultra-fine constitute the most significant hazard potentials. A study from Great Britain proves that the domestic fuel has the lowest share of respirable ultra-fine fine dust particles. It is particularly difficult to estimate the impact on human health because the effect depends on many factors. A decisive role apart from the size of the particles plays in particular the toxicity. Studies which have compared the toxicity of diesel and wood particles concluded that the smaller diesel particles with identical concentration in cell cultures are approximately 5 times more toxic than the significantly larger wood particles.
Originators and distribution
In Austria, the largest originators of fine dust are the industry, the small-scale consumers and the traffic. It is not that easy to determine how high the exact share of heating systems is in the sector of small-scale consumers. On the one hand, studies show a share of 17% in the production of fine dust, other studies on the other hand are speaking of an average value of 11%. What makes the assessment of the originators of particulate emissions more difficult is the fact that the particles have a high exposure time in the air due to their low mass and that they may therefore be transported over long distances. The values are also biased by precipitations and the topography of the site of measurement. The air is purged when it rains and snows and particularly high measured values are determined in regions located in basins and with less wind circulation. Up for discussion on European level have for several years been possible comparable measuring procedures for the correct acquisition of fine dust.
The tiled stove as an environmentally friendly contribution to climate protection
For some time now, the Austrian tiled stove association is developing a range of measures in order to promote research & development in this field on the one hand and to further reduce the emission of fine dust on the other hand. In doing so, the primary measures are the optimization of the combustion chamber geometry, the influence of the combustible and the behavior of the operator. The secondary measures include for example the use of filters. At present and at today’s state of research, there are three main arguments which may be quoted in favor of the tiled stove.
The tiled stove is 90% heated with the combustible wood which is CO2-neutral as is generally known. It is thus an important element of an environmentally friendly climate strategy.
Last year, approximately 110.000 Austrian households and businesses heated with wood pellets. Compared with heating oil extra-light, the intensive use of this ecologically indigenous combustible led to savings of more than 1.1 million tons of CO2.
Wood is available in plentitude in our region. It does not leave behind any debts to the nature because significantly more wood is growing back every year than is harvested.
The proportion of wood-fired heating systems in the total fine dust emissions only amounts to a maximum of 10-20%.
Needless to say that the tiled stove has a share in the entire fine dust emissions. But the dimensions are often misrepresented in the media. The major originator in Austria and Central Europe is still the industry. Decisive for potential hazards is not the quantity of the particles in the air but their size. According to this analysis, it is for example the fine dust from diesel soot which is much more hazardous than the fine dust from wood log heating systems.
Optimized combustion techniques in state-of-the-art tiled stoves do hardly cause any PM 10-emissions.
If we would replace old room heaters with modern combustion-optimized tiled stoves it would be possible to save approx. 90% of the current PM 10 emissions of those devices. Studies on the development of dust emission prove that the PM 10 level in the air is stagnating for years which is, although the energy demand has increased, attributed to a better quality of the used technologies.
For years, the Austrian tile stove association as well as the Austrian biomass association have been dealing with the information relating to the positive contribution of wood-fired heating systems for the environment.
Is the environmentally friendly tiled stove a fine dust offender?, Austrian tiled stove association, testing and research institute of Austria’s stove setters, 2007
Cost saver biomass, magazine ökoenergie, edition 112.000/94, Feb. 2014
Prof. Dr. Hobbauer H., The quantity alone says too little about health hazards, Austrian tiled stove association, 2009
Tausz C., Schiffert T., Fine dust – Where is the journey taking us? Austrian tiled stove association