Methods to measure Dust Production and Deposition Rates in Buildings

Abstract

Abstract Two parameter estimation methods were developed for the estimation of the rates of dust production and dust deposition. Both methods could be applied to occupied livestock buildings because they do not involve the need to take measurements within the animal pens. Experiments were conducted in a laboratory chamber using talcum powder as the aerosol to test the two methods. The steady-state method depends upon being able to hold all except one of the terms in the steady-state mass balance equation constant. In these laboratory tests, the term that was changed was the dust removal efficiency of the filtration system. The estimates of dust production rate were within 1 and 15% of the measured rate in two tests, while the estimates of dust deposition rate were within 1 and 18% of the measured rate in the same two tests. The unsteady-state method involved measuring airspace dust concentration versus time. The method provided accurate estimates of dust production and dust deposition separately for the data of Wadden and Scheff but not for the experimental data collected in this project. When the experimental data were used, only the net rate of dust production could be estimated, but these estimates agreed well with measured values. In laboratory studies with talcum powder as the dust, the ratio of dust deposition to dust production varied from 60 to 86%. These findings confirmed earlier hypotheses that dust deposition is an important means of removing dust from the livestock building airspace.