| Abstract [eng] |
The indoor climate in modern buildings depends on a variety of factors, such as air change rates, a presence of air pollutants, operative temperature, air distribution scheme, air velocity etc. Thermal comfort and indoor air quality in buildings are mostly influenced by the combination of heating, cooling and ventilation systems. To ensure high indoor air quality levels, it is important to either reduce emissions from pollutant sources or ensure effective removal of these emissions. The most significant air pollution sources in modern buildings are household chemicals, finishing materials and furnishings. To accurately assess the impact of air pollutant sources on occupants, particular attention should be paid to the isothermal pollutants released at the near-floor level, because of the human convective boundary layer ability to elevate pollutants to breathing level. The most frequent sources of such pollutants are floor coverings, cleaning products, varnishes and others that emit volatile organic compounds. Volatile organic compounds are produced by evaporation of materials at room temperature, and therefore they can be classified as isothermal pollutants. Furthermore, their density and temperature are not significantly different from the indoor air density and temperature. Therefore, the dispersion of such pollutants is influenced by indoor climate parameters (air temperature and air velocity), air distribution scheme and convective flows in rooms. Dispersion of volatile organic compounds released at a near-floor level under different combinations of heating systems and air distribution schemes was investigated experimentally in the full-scale test chamber and simulated using computational fluid dynamics software. It was determined that a combination of heating and air distribution schemes should be carefully considered in cases where sedentary activities are carried out in buildings and the presence of near-floor level emitted pollutants cannot be avoided. The focus should be on the heating system type, as the effect of air distribution is comparatively minor. |
