The purpose of this literature survey was to evaluate publications and other materials which addressed the subject of non-routine cleaning of ducts and other components of heating, ventilating and air-conditioning (HVAC) systems. In the first section of this report, we discuss the means used to identify particulate and odor contamination in HVAC systems, including typical building complaints associated with different types of contaminants, methods of airborne and surface sampling for contaminants, and problems associated with these two forms of identification.

The second section of the report focuses on a description of the types of duct work and HVAC components and systems which are most susceptible to particulate and odor contamination, the methods used to clean these components, and the level of success associated with different cleaning methods on different types of HVAC components and materials.

The third section of the report addresses the environmental and occupational health aspects of nonroutine cleaning of HVAC components. In particular, we address the hazards faced by employees and building occupants during cleaning operations.

The fourth section of this report focuses on the advantages and disadvantages of various methods used in duct cleaning in terms of the types of equipment to which they are most amenable, long term effectiveness, cost, short- and long-term hazards to people and the environment, the types of contamination for which they are most useful, and methods available for evaluating decontamination.

The final section of the report discusses some of our ideas for future work, based on the findings described in the previous sections.

As part of this literature search, two surveys were conducted. The first addressed a variety of issues associated with HVAC decontamination and was distributed to 31 businesses located throughout the United States. We attempted to obtain a cross-sectional view of the business from both geographic (six regions) and demographic (urban vs. rural) points of view. A copy of this survey and a summary of its results are included in Appendix A. We have incorporated some of the findings into the text of the report, as well.

The second survey involved telephone or in-person interviews with a variety of professionals from trade associations, academia, government agencies and consulting firms. A copy of this survey and a summary of its results are included in Appendix B. Again, the information from these surveys has been incorporated into the text of the report.