The Extraction Unit

Dislodging this material is only one part of the operation. The other being the safe removal of the contaminants from the duct network, and ultimately from the building. This is carried out by the Air Extraction Unit connected to the section of duct being cleaned.

This extraction unit consists of an electrically driven fan capable of moving large volumes of air at very high pressure, and a filtration system enabling the collection of the removed material without the possibility of contamination to the interior of the building.

The extractor incorporates three stages of filtration. The first is a a filter bag of type H filter medium and traps larger particles (95% at No.2 Dust)

The central filter is a disposable pre-filter which traps the particles somewhat smaller than the bag, with the final filter being one of two types. The first type of the two types of final filters is 95% efficient to an ASHRAE Test Standard 52-76. This traps almost all particles down to a very micron size, and is suitable for almost all applications. The second of the final filter options is a HEPA Absolute Filter with an efficiency rating of 99.9% at 0.03 microns. This filter is used in hazardous substance removal.