NADCA standards specify proper methods as well as the proper equipment to be used. NADCA requires surface agitation. This can be achieved through contact vacuuming with a HEPA filtered industrial vacuums on accessible parts of the HVAC system or with agitation devices such as mechanical brushes under negative air pressure and a collection system. Therefore, consumers should be on the watch for any company claiming to spray some magical chemical in to the system without using agitation and collection devices.
Proper HVAC Cleaning Process
There are two key components to HVAC cleaning: breaking
contaminants loose, and collection of contaminants.
Breaking Contaminants Loose
Properly cleaning HVAC systems requires removing the sources
of contamination. Source removal begins with use of one or
more agitation devices designed to loosen contaminants from
the surfaces within the heating and air-conditioning system.
Examples of agitation devices include brushes, air whips, and
compressed air nozzles or “skipper balls.” Agitation can also be
achieved through hand-brushing or contact vacuuming.
DUCTZ uses a rotating brush for agitation
to loosen contaminants
Collection of Contaminants
During cleaning, the entire HVAC system is placed under
continuous negative pressure (vacuum) to prevent the spread
of contaminants. Continuous negative pressure allows very fine
particles to be removed from the system as they become airborne,
ensuring that these particles are not released into the living space
when the system is turned on after cleaning.
This negative pressure also serves to extract the loosened
contaminants, which are collected and removed from your home.