Paper Conference

Proceedings of Building Simulation 2009: 11th Conference of IBPSA

     

VALIDATION OF THE INDOOR EXPOSURE MODEL FOR DWELLING LIFE CYCLE ASSESSMENT

Arjen Meijer

DOI: https://doi.org/10.26868/25222708.2009.0890-895
Abstract: Damage to human health as a result of exposure to contaminants emitted to indoor air is poorly addressed in life cycle assessment tools for dwellings. A new model is available to calculate damages to human health caused by contaminants emitted from building materials, using a multizone indoor airflow and exposure model. Ventilation rates and radon concentrations have been simulated for the Dutch reference dwelling and are compared with measurement data from the Dutch Ecobuild houses and from average ventilation rates and radon concentrations in dwellings in the Netherlands. The ventilation rates and radon concentrations as simulated with the indoor exposure model have the same order of magnitude as the ventilation rates and radon concentrations measured in the Ecobuild dwellings and in both radon surveys, except for the crawl space, where the modelled ventilation rates are overestimated and the radon concentrations are underestimated. Overall, the indoor airflow and exposure model gives a good reflection of actual ventilation rates and radon concentrations, but for the crawl space, the model needs to be adjusted, and the effects of mechanical ventilation on the model results need to be tuned to practice. emission and exposure part of the methodology. Exposure to radon is considered in this research, because radon is emitted mostly from stony building materials and from the soil, and occupant behaviour has little influence on the radon levels in the dwelling. In this research, radon exposure levels calculated with the new methodology are compared with measurement data from two Dutch radon surveys and from the Ecobuild project (Stoop et al., 1998; Hasselaar, 2002; Blaauboer et al., 2008). METHODOLOGY Simulation In the LCA methodology, characterisation factors can be used to calculate the combined environmental damage occurring in the life cycle of a product (Heijungs and Hofstetter 1996). For radon emitted from building products, characterisation factors can be used to link the total amount of radon exhaled during the lifetime of the building material to human health damage. The damage score for the use phase of building material p as a result of emission of radon is expressed in terms of Disability Adjusted Life Years (DALY), which is the weighted sum of Years Lived Disabled (YLD) and Years of Life Lost (YLL), and can then be calculated by:
Pages: 890 - 895
Paper:
bs2009_0890_895