# The Impact of Solid Fuel Residential Boilers Exchange on Particulate Matter Air Pollution
###### Abstract  
Combustion processes, including the use of solid fuels for residential heating, are a widespread custom for many households. Residential heating is a significant source of ambient air pollution, yet it varies greatly by geography, meteorologic conditions, the prevalence of the type of solid fuel and the technologies used. This study evaluates whether residential heating affects the air quality through modelling three given scenarios of solid fuel boiler exchange at selected locations and comparing the results with measured data. The findings of this study suggest that according to the modelled data, the main air pollution contributor is residential heating since Dolni Lhota (daily average of PM\({}_{10}\) = 44.13 \(\upmu\)g\(\cdot\)m\({}^{-3}\)) and Kravare (daily average of PM\({}_{10}\) = 43.98 \(\upmu\)g\(\cdot\)m\({}^{-3}\)) are locations with no industry in contrast to heavily industrial Vratimov (daily average of PM\({}_{10}\) = 34.38 \(\upmu\)g\(\cdot\)m\({}^{-3}\)), which were modelled for the heating season situation. Nevertheless, actual measurements of PM\({}_{10}\) during the same period suggest that the average levels of air pollution were significantly higher than the modelled values for Dolni Lhota by 64% and for Kravare by 51%. Thus, it was assumed that PM long-range or/and transboundary transports were involved. residential heating; boiler; air pollution; PM\({}_{10}\); dispersion model; long-range transport 2021 9 June 2021 10 June 2021 The major problem with the burning of solid fuels is that the devices used for household heating incompletely combust the fuel causing their low combustion temperature and other limitations. This results in producing relatively high emissions of incomplete combustion per unit of fuel, such as primary particulate matter (PM\({}_{10}\) and PM\({}_{2.5}\)) and carbon monoxide (CO)--major air pollutants. Furthermore, black carbon (BC) emissions (a component of PM\({}_{2.5}\)) can evolve during small-scale solid fuel combustion, causing climate warming [8]. By 2020, residential wood burning in Europe will become the dominant source of PM\({}_{2.5}\)[9]. When using coal for residential heating, additional emissions are produced, such as sulfur and other toxic contaminants found in some types of coal [10]. Nevertheless, household-level emission controls or regulations are often lacking. The recommendations on PM emission limit values for residential combustion installations with a rated capacity of less than 500 kW hours are given in the 1999 Gothenburg Protocol under the Convention on Long-Range Transboundary Air Pollution. The recommended emission limit values for PM depend on the type of fuel (wood: 75 mg/m\({}^{3}\); wood logs: 40 mg/m\({}^{3}\); pellets and other solid fuels: 50 mg/m\({}^{3}\)) [11]. In most countries, there are regulatory measures available to reduce solid fuel emissions for residential heating. Principally, they encourage fuel switching (away from coal and other solid fuels), the use of more efficient combustion technologies (e.g., automatic feeder pellet stoves or certified fireplaces), the introduction of district heating and in-home high-efficiency particulate air (HEPA) filtration, which all lead to the reduction of emissions [12]. Existing regulatory measures include Commission Regulation (EU) 2015/1189 implementing Directive 2009/125/EC regarding ecodesign requirements for solid fuel boilers and Regulation (EU) 2015/1187 supplementing Directive 2010/30/EU with regard to energy labelling of solid fuel boilers and packages of a solid fuel boiler, supplementary heaters, temperature controls and solar devices. The limit values of codesign requirements for PM emissions, valid from the 1 January 2020, are 40 mg/m\({}^{3}\) (automatically stoked boilers) and 60 mg/m\({}^{3}\) (manually stoked boilers), which are mandatory for all manufacturers and suppliers in the EU countries [13]. These values are equivalent to the class 5 requirements specified in the EN303-5:2012.