THE EFFECT OF DUCT CLEANING ON INDOOR AIR QUALITY IN OFFICE BUILDINGS

摘要

The effect of duct cleaning on supply air quality, duct cleanliness, air exchange and working environment was studied in 15 non-problem office buildings. Mass and number concentrations of particles, concentrations of microbes, volatile organic compounds and CO_2 were measured in outdoor, supply and indoor air. Samples of accumulated dust were taken from the inner duct surfaces and supply and exhaust air flows were measured. An Indoor Climate Questionnaire was delivered to over 900 employees before and after the duct cleaning. Duct cleaning had no measurable effect on supply air quality. The results showed that the average amount of dust on the inner duct surfaces decreased from 8.4+-9.1 to 1.9+-2.1 g/m~2. The employees perceived the working environment better after the cleaning than before it.