HVAC cleaning comments by [name] Associates, Jan 2003

NYC 9/11 Public Portal Document

Draft2 Comments by Covino Environmental Associates, Inc. January 6.2003

Use isolation/zone pillows as necessary to isolate sections of the system, so that sufficient negative pressure is maintained in each work zone and to prevent cross-contamination of cleaned sections by work in sections not vet cleaned.

-7.06eupied areas or common areas in -which-fan unit cleaning is accomplished, will be cleaned as common spaces using the-eemmon space unit prices, immediately after the HVAC oleamng is-complete.

S.These areas identified in 6 above will-be air tested immediately after cleaning of the eommen space and analysis will be accomplished on a RUSH basis.-These-areas should not be opened for re oocupancy-until successfal results aren-eceived.

9. A local c-apture, HEPA filtered, Air Filtration Device (AFD) will be attached to the lowest opening of a riser or the furthest point of a horizontal duct, to place the system under negative pressure.

lO.Insert and inflate 4solation/zone- pillows, as necessary 40 isolate system, so that the cleaning does not extend outside the work zone.

11 .Remove-and clean all grills along the affected ductwork.

12.Clean all branch ducts using HEPA vacuums with-brush attachments and wet methods.

13. Apply encapsulant to any exposed porous insulation in the AC/ventilation system fan unit or ducts.

14. Protect the floor underneath the supply grilles/diffiisers or return air grilles using 6 mil polyethylene sheeting. Remove the polyethylene barriers covering the supply air diffusers/grilles and return grilles, while the duct is still under negative pressure.

13.Reinstall grills and install-one layer of 6 mil poly-over grills and secure in place with painters tape.

15. Remove supply air grilles and diffusers to a central location for cleaning. Clean using Simple Green or a similar environmentally safe product. Use bags if necessary when removing the grilles and/or diffusers to prevent dust or debris from being released. Reinstall supply grilles/diffitsers and return air grilles after cleaning.

IdTClean-die main duct starting from the furthest point away from the local of^ture-AFD? (usually at the fan unit)r-using-a combination of techniques including whips, brushes, and compressed-air xmtil no suspect WTC dust is apparent.

15.Remove- the-poly barriers, covering the exhaust gills, while the duct-is still under negative pressure se-that-any loose dust or debris will be sucked into the capture system.

16. Remove and replace air filters within the AC/ventilation system fan unit or ducts.

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