A simplified analytical model of ultrafine particle concentration within an indoor environment

Abstract

Exposure to indoor fine and ultrafine particulate matter (PM) has been recognised as a fundamental problem as most people spend over 85% of their time indoor. Experimental data derived from a field campaign conducted in a confined environment have been used to investigate the physical mechanisms governing indoor-outdoor PM exchanges in different operating conditions, e.g. natural ventilation and infiltration. An analytical model based on the mass balance of PM has been used to estimate indoor fine and ultrafine PM concentration. Indoor-outdoor concentration ratio, penetration factor and air exchange rate have been estimated and related to the differential pressure measured at the openings.