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Published March 1990 | public
Journal Article

Particle Deposition in Museums: Comparison of Modeling and Measurement Results

Abstract

Deposition of airborne particles may lead to soiling and /or chemical damage of objects kept indoors, including works of art in museums. Measurements recently were made of the deposition velocity of fine particles (diameter range: 0.05–2.1 μm) onto surfaces in five Southern California museums. In this paper, theoretical predictions of particle deposition velocities onto vertical surfaces are developed for comparison against the experimental results. Deposition velocities are calculated from data on surface-air temperature difference and near-wall air velocity using idealized representations of the air flow field near the wall. For the five sites studied, the wall-air temperature differences were generally in the range of a few tenths to a few degrees Kelvin. Average air velocities measured at 1 cm from the wall were in the range 0.08–0.19 m s^(−1). Based on a combination of modeling predictions and measurement results, the best estimate values of deposition velocity for the wall studied at each site are obtained. These values are in the range (1.3–20) × 10^(−6) m s^(−1) for particles with 0.05–μm diameter and (0.1–3.3) × 10^(−6) for particles with 1-μm diameter. The range of 15–30 in deposition velocity for a given particle size is due primarily to differences among sites in the near-wall air flow regime, with the low and high values associated with forced laminar flow and homogeneous turbulence in the core of the room, respectively.

Additional Information

© 1990 Elsevier Science Publishing Co. Received: 19 Jun 1989. Accepted: 12 Jan 1990. Financial support for this work was provided through a contract with the Getty Conservation Institute. Additional support was received through graduate scholarships from the Switzer Foundation and the Air Pollution Control Association, and through summer undergraduate research fellowships from Caltech. We thank Harvey Liu, Mike Jones, Theresa Fall, Lynn Salmon, and Paul Solomon for their assistance in obtaining the experimental data. The SEM analyses were carried out at the Air and Industrial Hygiene Laboratory of the California Department of Health Services, Berkeley, California. The active support and cooperation of the staffs of the five study sites is gratefully acknowledged.

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023