Abstract |
Air velocities have been measured in the master bedroom, kitchen, and basement of six occupied homes plus the dining/living room area of one unoccupied house. All of the houses have central, forced-air heating and air conditioning (HVAC) systems. Median air velocities of 5.3 and 12.4 cm/s were measured in all six occupied houses and the unoccupied house, respectively. Median velocities of 4.2, 4.3, and 10.2 cm/s were found in the master bedroom, basement, and kitchen of the six occupied homes, respectively. The elevated air velocities in the kitchen are consistent with increased occupant activities and use of ceiling and/or exhaust fans. The lowest median velocity of 1.1 cm/s was found in the master bedroom (with the forced air circulation off) where occupant entry and activities were purposely limited. Switching on the forced-air HVAC systems increased the median velocities from 5.8 to 6.2, 3.2 to 5.7, 1.5 to 8.1, and 4.4 to 15.5 cm/s in three occupied houses one unoccupied house, respectively, where the experimental data allowed such comparison. Low air velocities may sometimes be inadequate for quantitative passive monitoring of pollutant vapors. Ten and 50% reductions in sampling rate are noted from the literature for passive monitors at air velocities of <0.7-25 cm/s and <0.7-2 cm/sec, respectively. 14 refs., 6 figs. (ERA citation 13:018425) |