Development and application of a protocol to evaluate impact of duct cleaning on IAQ of office buildings

Field investigations reporting increased airborne particles concentrations after ventilation duct cleaning (DC) and emissions of biocides following its use in DC highlight a need to protect building occupants from possible exposures to these harmful pollutants. A new protocol was developed to include tests for assessing duct surface cleanliness and harmful airborne pollutant concentrations associated with DC. Two office buildings undergoing DC were chosen to demonstrate the protocol application. The new protocol was tested for surface cleanliness assessment using a combination of visual inspection and a vacuum test method wherever possible. For airborne pollutant concentration assessments, indoor air exposures to total particle, fungi and VOCs were measured. The test application demonstrates that it is possible to determine harmful airborne pollutant concentration levels attributed to DC activities while still maintaining industrial performance standards of surface cleanliness.