Emissions from Irish domestic fireplaces and their impact on indoor air quality when used as supplementary heating source

A field study on the impact of fireplace on the indoor air quality was carried out between 2004
and 2006, where two main contaminants, CO and particulate matters, were investigated in
twenty seven randomly selected Irish houses. The results show that while the physical
environment has been improved by increasing the room air and radiant temperature, indoor
air quality is significantly decreased when fireplace is used as additional heating source to the
central heating. The operation of fireplace increased transient concentrations of CO and
airborne particle to several times higher than the normal house average level. Statistical
analysis showed significant difference of the average PM10 concentration between house
groups with and without using fireplace. However fireplace did not demonstrate a significant
influence on average CO level from our samples. When comparisons were made between
houses with various emission sources, i.e. fireplace, smoking and open fire gas cooking, and
houses free of the above sources, smoking and open fire gas cookers were proved to be
other major sources of particles and CO. Particularly when they exist at the same time with
fireplace, significant elevation of CO and airborne particle levels is observed in analysis.
Cumulative probability analysis in some houses revealed high percentage of time exceeding
health guidelines which indicated the potential health risk in these houses. Mass balance
equation was employed to estimate particle emission rates from fireplace, namely 0.66 mg
min-1 (PM10) and 0.20 mg min-1 (PM2.5) respectively in terms of mass concentration.
Emission rates on particle numbers were also estimated despite the relatively smaller sample.
Gas fuel fireplaces tended to emit fewer particles both in mass and in number comparing to
fireplaces using solid fuels.