A device for generating a condensation aerosol includes vaporization chamber having an upstream first inlet and a downstream outlet. A tube supplies liquid to a heater in the vaporization chamber. The liquid is pumped out of the tube and onto the heater, which vaporizes the liquid. Air flows from inlets through the vaporization chamber, and generally perpendicular to the tube. The vaporized liquid is entrained in the air, forming a condensation aerosol having a particle size in a selected range. A second inlet provides a substantially laminar flow of air into the airflow path, wherein the second inlet is downstream of the heater; and the device capable of changing air flow in the vaporization chamber to change the particle size of the condensation aerosol and/or to change the amount of visible vapor emitted from the device.