Abstract
Five portable space heaters with different heating mechanisms, electrical heating and liquid fuel combustion, were studied for their particulate emissions in a 31 m3 room with a ventilation rate of 3 air-changes/hr and in an 11 m3 air-tight chamber. The electrical space heaters included three conventional types having different heating elements — a heavy coil, a thin strip and a fine coil — and one new-style quartz heater in which the heating element is enclosed in a quartz tube. The liquid fuel heater was a modern type of kerosene burner with a wire heating mantle housed in a heat chamber. The conventional electrical heaters produced ultrafine particles, while the quartz and kerosene heaters released larger particles of up to 3 µm in diameter. The particle number and mass concentrations were in the ranges of 104 – 106 particles/cm3 and 1–300 µg/m3, respectively. The kerosene heater released 1 to 2 orders of magnitude more particles, both in mass and number, than the other heaters. These particles were composed of a mixture of individual solid and hollow spheres with sizes up to 0.3 µm, and clusters and chain aggregates in the range of 0.1 to 3 µm.