
|
 |

A HISTORICAL PERSPECTIVE OF AIR DUCT CLEANING
It is important to realize that air duct
cleaning is more than just cleaning the air
ducts. Air duct cleaning must also include
cleaning of the air handling unit (AHU), the
return air system - - every component of the
air distribution system.
In the past, most of the air duct cleaning work was for
residential customers, and was performed with
truck-mounted systems with huge canvas
vacuum bags, The air duct cleaner would hook
up a hose from the truck to the furnace and
attempt to " suck all the dust and debris
out of the system ". This practice was
ineffective at best since it is virtually
impossible to vacuum debris from one single
point without some means of agitation, like
air washing or power brushing.
This is not to say that all duct cleaners were making one connection
and essentially scamming the customer.
Many companies took the time to cut a
series of access points in the duct system
which enabled them to perform a reasonably
quality job, given the limitations of the
knowledge, traning and equipment available at the time.
Due to an increase in indoor air quality awareness, several
vacuum-truck and portable equipment
manufacturers emerged. The industry's limited
advancements to that point included electric
hand-held blowers (leaf Blowers) to assist in
dislodging loose dirt from the extreme ends of
the ductwork system. However these blowers
only served to move loose debris a few feet.
Air compressors were introduced as a more
effective alternative to portable blowers.
Their increased air pressure and velocity
provided a means to loosen and move the
contaminants within an air duct system to a
point where they could be vacuumed. Their use
was followed by the development and use of air
skippers or rotary sweeps.
The skipper consists of a machined ball
with a series of holes attached to the end of
a long flexible air hose. By triggering
compressed air into this device, the skipper
propels itself through ducts while air washing
them at the same time. Today compressed air
washing is augmented by manual scrubbing with
brushes and flexible rods, as well as powered
rotary brushes. These technologies allow
contractors to effectively clean hard to reach
areas within the duct system.
In addition to air duct cleaning being
recognized as a standard mechanical practice,the Environmental Protection Agency
(EPA) recently published preliminary recommendations on Air
Duct Cleaning in its Building Air Quality
handbook. The EPA's recommendations include
the following:
- Whenever possible, air duct cleaning
should be scheduled during periods when the
building is unoccupied. This is because the
Air Duct Cleaner can be most productive when
not having to work around building occupants.
- Negative air pressure to draw
pollutants to a vacuum system should be
maintained at all times.
- Only high-efficiency particle arrested
(HEPA) vacuuming equipment should be used on
the vacuuming equipment, especially if it
exhausts into the occupied area.
- Careful attention must be given to
protecting the ductwork (some have limited
access - - use existing openings where
possible, and carefully repair any damage
caused when forced to cut new entryways).
- If biocides are to be used, then
select only products registered by the EPA for
such use, use the products according to the
manufacturer's directions, and pay careful
attention to the method of application.
- Water-damaged or contaminated porous
materials (fiberglass duct board, interior
insulation) in the ductwork or other air
handling system components should be cleaned
and coated or sealed or removed and replaced.
The Environmental Protection Agency (EPA) also released a study on in October 1996,
Indoor Air Quality - Basics for Schools.
covering topics effecting the health of our children in public schools.
The Department of Energy (DOE) published a summary of sceintific research in January 1999,
Causes of Indoor Air Quality Problems in Schools futher supporting the need to take Indoor Air Quality as a serious health issue.
Today, a combination of improved equipment
and training along with an ever growing number
of contractors getting into the business, has
helped emerge the air duct cleaning industry
so that it is recognized for its benefits
towards improving Indoor Air Quality (IAQ).
In addition to air duct cleaning, there
are several other areas where the IAQ
contractor has entered into this new
marketplace. These include educating Builders
and Real Estate Professionals as to the
importance of indoor air quality, not only as
a health consideration, but as an effective
marketing tool to promote customer
satisfaction and retention. Testing and
Monitoring Services, IAQ Management Services,
and equipment sales of products designed to
enhance indoor air quality, such as Energy
Recovery Ventilators (air-to-air heat
exchangers), high efficiency filters
and humidifiers have emerged.
What ever your interest in Indoor Air
Quality might be, it is important that you
recognize the NATIONAL AIR DUCT CLEANERS
ASSOCIATION NADCA
and its member �certified� companies as responsible professionals in the
IAQ Industry.
809 Live Oak Drive, Suite 30 Chesapeake, Virginia 23320-2600
Ph: 757-366-5237 | E-mail: [email protected]
|