The Cook's Air: Room Smoke Concentration Over a Cooking Day, and the Opening Size That Holds It Down

A single well-mixed box model follows fine-particle smoke through a stated cooking day in a 30 m3 kitchen where a wood fire emits 120 mg/min during 6.0 hours of cooking. In a closed room with 0.5 air changes per hour the concentration peaks at 350.71 mg/m3, the average over the 14.5 hour day is 150.45 mg/m3, and the cook's accumulated exposure is 2181.5 mg.h/m3. A roof gap of 0.05 m2 lowers the day average to 23.46 mg/m3, a window of 0.15 m2 to 8.75 mg/m3, and a door opening of 0.20 m2 to 6.66 mg/m3 - every one of these common arrangements fails the stated criterion of a day average below 2.0 mg/m3. Holding the average at that criterion requires an opening of 0.686 m2 under the stated discharge model, about 49.42 air changes per hour while the fire burns. Doubling the room to 60 m3 halves the closed-room average to 75.22 mg/m3 but barely helps once an opening is present (6.37 mg/m3 with the same door opening) and barely changes the required opening, to 0.677 m2: room size dilutes a sealed room, but ventilation area, not volume, governs a ventilated one. SIMULATED, NOT MEASURED.