emissions

In order to evaluate the impacts of volatile organic compounds (VOCs) emissions from building materials on the indoor air quality beyond the standard chamber test conditions and test period, mechanistic emission source models have been developed in the past. However, very limited data are available for the required model parameters including the initial concentration (Cm0), in-material diffusion coefficient (Dm), partition coefficient (Kma), and convective mass transfer coefficient (km).

The IEA EBC Annex 68 project on “Indoor Air Quality Design and Control in Low Energy Residential Buildings” has been recently completed. The project considered indoor air pollution loads in dwellings, particularly how such pollutants are emitted in dependency of the hygrothermal conditions: temperature, moisture and air flows. Thus, a proper understanding of the mutual interactions between hygrothermal conditions and pollutants was needed to obtain optimal paradigms for demand-controlled ventilation.

Traditionally, occupancy-based ventilation controls have only ventilated when occupants are present – usually based on measurements of CO2 and/or humidity.  These indictors may be fine for pollutants released directly by occupants, such as bioeffluents, or by their activities, such as cooking and cleaning. However, they do not account for pollutants not associated with occupancy, such as formaldehyde from building materials and furnishings.

INTRODUCTION: The Finnish Society of Indoor Air Quality and Climate (FiSIAQ) introduced over twenty years ago in 1995 a Classification of Indoor Climate, Construction Cleanliness, and Finishing Materials and the third edition will be published autumn in the year 2017. Based on the criteria set in the classifications, The Building Information Foundation RTS sr started the M1-labelling of air handling components in 1999. Name of the classification is Cleanliness Classification of Air Handling Components.

Formaldehyde, less-volatile aldehydes, and terpene hydrocarbons are generally the predominant air contaminants in new manufactured and site-built houses. This study was conducted to identify the major sources of these compounds in a typically constructed, new manufactured house. Specimens of materials used within the house envelope were collected from the production facility. These were individually preconditioned for 19 4 days and tested for emissions of formaldehyde and the other target compounds using small-scale chambers.

Building products, furniture and other products used indoor influence the indoor air quality. This implies that ventilation is not the only method to ensure good IAQ. Pollutant load reduction by using low-emitting materials is a far more effective way to improve the air quality inside a building. Measurement of chemical emissions is not enough to characterise the impact building materials have on indoor air quality.

A simplified indoor air quality (IAQ) model has been applied to predict IAQ in an Australian house, using environmental chamber measurements of source strengths, house ventilation and room size. Total volatile organic compounds (TVOCs) was used as the model pollutant in this study. The validity of the IAQ model was initially assessed by comparing model predictions with measurements in the house over a period of time. The root mean square error between the measured and predicted values was 0.039. This model explains 57% of the potential for error.

Although a significant amount of work has been done to elucidate the conditions under which fungi will grow on the surfaces of materials, little information is available that quantitatively relates surface concentrations to airborne concentration and, ultimately, exposure. This paper discusses the impact of relative humidity (RJI), air velocity, and surface growth on the emission rates of fungal spores from the surface of contaminated material.