June 10, 2008
What is required for effective air duct cleaning in mold
Tampa, Fl -- WATE 6 TV recently headlined a story entitled
“Businessman takes woman's money, never cleans mold or repairs carpet”
exemplifies the charlatan and shaman mentality of many of the so called "IAQ
experts" that prey on the unsuspecting public. This activity has grown to
epidemic proportions. Indoor Air Quality issues are rapidly becoming part of
the general public’s consciousness through the mass media’s portrayal of
proliferating toxic mold. Many Floridians, along with the rest of the nation
are now discovering that non-qualified commercial mold remediation firms and
residential duct cleaning services can be just as hazardous.
Numerous post-hurricane mold cleanup efforts have been ineffective. A recent
article stated that 40 percent of the certified duct cleaners do not follow
their certifying entity’s procedures and protocols. Many states are rushing
to introduce legislation that qualifies and regulates the currently
unregulated remediation industry. At this point, the question must be asked:
Does air duct cleaning or mold remediation really help improve IAQ?
The first step to consider before embarking on a duct cleaning or mold
remediation project is to determine the hygiene condition of the HVAC system
and the potential sources of mold. Keep in mind, the source of a mold
problem may not be visibly apparent, and just cleaning the ducts may not be
the answer. Contact a reputable environmental consultant who can conduct an
indoor environmental walkthrough that includes a pragmatic series of
diagnostic tests to determine the environmental baseline status of your home
What does Duct Cleaning or Mold Remediation Entail?
Mold Remediation includes a large variety of components (e.g. drywall, wood,
carpet, building furnishings, etc.), which may also include duct cleaning.
The type of mold, levels of contamination, and clearance levels will
determine the protocols employed during the remediation project. It is
important that the remediation service provider environmentally clean all
the contaminated components so unclean sections will not re-contaminate the
home or office again.
Anti-microbial chemicals are sometimes applied during the cleaning process
and in some cases incorporated into the encapsulating products. Ensure all
chemicals used are EPA registered for the specific application. All MSDS
sheets should be maintained on the project worksite. Some newer remediation
efforts include cryogenic processes for mold treatment.
Duct cleaning entails cleaning the various heating and cooling system
components of forced air systems. These components include the supply and
return air ducts and registers, grilles and diffusers, heat exchangers
heating and cooling coils, condensate drain pans (drip pans), fan motor and
fan housing, variable area volume (VAV) boxes, fresh air ductwork, and the
air handling unit housing.
The service provider should take preventive steps to protect individuals
from exposure to dislodged contaminants during the cleaning process. These
steps may include the use of containment barriers; the utilization of
negative air machines (NAM) employing High Efficiency Particulate Arresting
(HEPA) filtration rated 99.97% efficiency for particulate size of .03
microns on the cleaning equipment, effective “tools of the trade” to
facilitate proper removal, and the use of employees who are trained in OSHA
In an office type building, remediation should be performed at night, to
again minimize the occupational disruption of the tenants and potential
contaminants disturbed during remediation processes.
Signs of Mold:
The most efficient means of determining the presence of mold is through
indoor environmental surveys. Often, building occupants exposed to mold
contamination experience allergic symptoms, asthma attack, etc. Some non-ideopathic
entities like rapid changes in air temperature and humidity levels, building
pressurization, fluctuating lighting, and odor-causing evolutions can elicit
similar symptoms and sometimes even can mask a mold-related problem.
Mold requires moisture for growth. Moisture intrusion due to poor
construction design, materials, laborers, and technique is currently a major
industry problem. There are currently no regulations for mold contaminant
levels, but there have been multiple bills introduced at the various levels
of government (federal and state) with regulation coming in the not too
Opportunistic pathogenic molds are well documented as well as others that
generate toxic chemicals (MVOC’s). Even if you have visible mold present,
reputable professionals should do the qualification and quantification with
all assay analyses performed by an accredited laboratory.
Guidelines for acceptable levels of molds have been developed through trend
analysis of the Computer Assisted Air Management Program Systems (CAAMPS) at
the Environmental Diagnostics Laboratory of Pure Air Control Services (www.pureaircontrols.com).
CAAMPS contains data from over 100,000 samples collected in over 500 million
sq. ft. of commercial and residential sites during 10,000 indoor
Signs That Ducts Should Be Cleaned:
Several factors help determine if the duct system should be cleaned. One
major factor is visible mold growth inside hard surface ducts or on other
components of your system. Be aware that although a substance may look like
mold, it may not be. The use of an AIHA accredited environmental laboratory
will accurately determine whether a sample is mold or simply debris that
If the air duct insulation is saturated with water, it should be removed and
replaced and the cause of the growth corrected before the cleaning or
Other factors include rodent or insect infestation and a clogged HVAC system
that actually releases contaminants into the building or home through the
If proper mold remediation or duct cleaning procedures are not followed,
these processes can cause more dust, debris, and molds to be released into
the air. Inadequate negative air machine collection systems and poor
containment can cause this problem.
Also, there is the possibility the service provider can damage your ducts or
heating and cooling system, which could result in increased heating and air
conditioning operational costs, expensive repairs or replacements.
Listed below are questions that should be posed to the prospective
remediation and duct-cleaning contractor:
• Are the New York City Department of Health Mold Remediation Guidelines
level I through level V being utilized for mold cleanup? • Is the company
NADCA certified and in good standing?
• Are the NADCA ACR 2002 specifications utilized?
• Are the IICRC Standard for Professional Remediation S520 utilized?
• Do they maintain adequate insurance coverage’s? e.g. Professional
Liability (E & O) $5M w/$1M mold remediation coverage; Contractor Pollution
Liability $5M w/ $1M mold remediation coverage; General Liability $1M w/ $2M
aggregate; Workers Compensation $1M; Automobile $1M,
• How long has the service provider been in business? • Is their work mostly
residential homes or commercial buildings?
• Does their respective state’s Department of Business and Professional
Regulation (DBPR) require licensure?
• What are the qualifications of the firm?
• Do they guarantee their work?
• What is the guarantee?
• Does the firm work with the medical community? (Health implications of
• Are their chemicals registered with the EPA for specific ductwork
applications? (Fiberglass vs. Sheet Metal)
• What quality control/quality assurances (QA/QC) protocols do they provide
to assure that mold, fiberglass, dust, pollen and dander have been
effectively removed after the cleaning process?
• Are the technicians who will be performing the work environmentally
• What are their backgrounds? Their experience? Have they been trained in
the following OSHA programs:
• Respiratory Protection Program: 1910.134
• Hazard Communication Program: 1910.120
• Confined Space Program: 1910.146
• Lock Out - Tag Out Program: 1910.147
Detailed environmental HVAC and Mold project remediation specifications are
essential in any indoor environmental remediation project and should be
mandated to confirmed the qualifications of the individual as well as
provide some assurance of the project’s success. Duct cleaning & mold
remediation works….if done right.