Mixing of a Point Source Pollutant by Natural Convection Flow within a Room

摘要: Indoor air quality models are commonly based on the assumption of instantaneous and complete mixing within a zone. Such an is not appropriate for all circumstances, such as investigating utility segregating smokers to reduce nonsmoker exposure environmental tobacco smoke. This experimental study characterizes quantitatively rate at which smoke from cigarette disperses unoccupied, 31-m3, low air-exchange room under natural convection flow conditions. Sidestream smoldering was simulated with pulsed release tracer gas – neutrally buoyant mixture sulfur hexafluoride (SF6) in helium above electrically heated coil. During each run, sequential samples were collected remotely, using gas-tight syringes, 41 locations room. After these analyzed SF6 content chromatograph electron-capture detector. Duplicate runs conducted three conditions: nearly isothermal surfaces; 500–watt heater; incoming solar radiation. Characteristic times ranged 7–10 minutes radiation case 80–100 case.