Comparison between full- and small-scale sensory assessments of air quality

Thirty-nine untrained subjects made small- and full-scale evaluations of the acceptability of the quality of air at 22 deg.C and 40% RH, polluted by either carpet, felt floor covering, painted gypsum board, linoleum or chipboard. Small-scale evaluations were made on the air extracted from 200-L glass chambers ventilated at an airflow of 0.9 L/s.

Full-scale assessments were made immediately upon entering offices ventilated at an outdoor air supply rate of 1.9 h-1. The ratio of ventilation rate to surface area of a building material was identical in the chambers and in the offices. Full-scale sensory ratings of acceptability of air polluted by carpet and by linoleum were systematically better than small-scale assessments, but not for the other three materials.

Calculated sensory emission rates from carpet and linoleum were significantly lower in full scale than in small scale. When modelling the perceived air quality in spaces, sensory emission rates estimated in small scale may require a correction, probably depending on the nature of the chemicals emitted by a building material.