HVAC cleaning procedures technical questions comments, Jan 2003

NYC 9/11 Public Portal Document

Procedure 5. Delete: through a window. This does not apply to outdoor units and there are no windows in most basements making it impossible. I have been told by equipment manufacturers that it is not recommended to run two vacuum collection systems in tandem, as it creates a backpressure that can damage the equipment or cause gasket leaks. DOP testing should be by others (Athenica).

Procedure 6. Painters tape is preferable especially for wall mounted grills. Procedure 7. Is containment required for outdoor/roof mounted units or units that are not in spaces accessible to the public? Define "containment".

Procedure 8. Some toilet vents are fabricated of sheetrock. Nylon brushes should be used. Exhaust ducts should be modified as appropriate.

Procedure 10. SSC does not feel it is necessary to wet clean thermal coils for the purpose of this cleaning and does not recommend wet cleaning of coils on outdoor units during the winter months.

Procedure 11. Does not address branches that are greater than 6 feet. When using whips, brushes etc., is a containment reguired?

Procedure 14. SSC recommends removing and cleaning the supply air grills, fire dampers and branch ducts before cleaning the main supply duct as cleaning of these areas after cleaning the main riser may lead to recontamination. Again we should work from the furthest point from the vacuum collection system.

Procedure 15. All filters should be removed and disposed of without discrimination.

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