“I now own three Vornados and a small army of those in-window units, strategically placed so that no particle of air stagnates in my 1,000-square-foot home. The resulting vortex of moving air eliminates any chance of particle buildup, of a heaviness of atmosphere taking root. Light a cigarette anywhere in my house, and you’ll be dazzled by the flow of the smoke—up and around, through doorways, swirling toward the ceiling and then back to the floor, inscribing elegant arcs through the air—never resting until it finds its way out a window.” Craig Mod in The Atlantic: How I Mastered the Art of Ventilating My Home. (I have a similar setup when I’m in an enclosed space with my two beagles.)