This paper presents the development and experimental characterization of a prototype
ultrafine particle concentrator. In this system, ultrafine particles pass over a pool of warm
water where they become saturated with vapor, and subsequently drawn through a
condenser, kept at a lower temperature, that allows the ultrafine particles to grow to super-
micrometer size by vapor condensation on their surface. In order to increase particle
concentration, the grown particles are drawn through a virtual impactor with an approximate …