Industry-Leading Training Programs

Duct cleaning has existed for more than fifty years, originating in the northwestern United States. New advancements in technology and cleaning processes for use in humid climates have revolutionized the industry within the last 15 years. The industry-leading principles and practices employed by DUCTZ professionals have helped to advance the industry by creating new, patented duct cleaning processes. DUCTZ continues to lead the way in certification, training and development of standards.

The National Air Duct Cleaners Association (NADCA) certification is the recognized benchmark for trained and qualified professionals. Through certification, NADCA members demonstrate their knowledge and proficiency in conducting HVAC assessments, cleaning, and restoration services. DUCTZ professionals are NADCA members in good standing and are trained to the NADCA standards.

DUCTZ has more certified Air System Cleaning Specialists (ASCS) than any other national organization. DUCTZ requires that each team leader holds a certified ASCS designation to work in your home helping to ensure that all cleaning is performed in accordance with NADCA standards. Additionally, DUCTZ has instituted an in-house training program to expand the commercial and residential capabilities and expertise of owners and technicians beyond the certifications offered by NADCA.

NADCA TRAINING AND CERTIFICATION

AIR SYSTEMS CLEANING SPECIALIST

The Air Systems Cleaning Specialist (ASCS) certification by NADCA signifies a high level of knowledge in the cleaning and restoration industry. Through certification, trained personnel demonstrate requisite knowledge of heating, ventilating and air conditioning (HVAC) system cleaning, NADCA standards, ACCA standards and OSHA safety regulations. By passing a rigorous NADCA certification examination, DUCTZ professionals achieve a reputation of reliability and competence.

CERTIFIED VENTILATION SYSTEM INSPECTOR

NADCA Certified Ventilation System Inspectors (CVSI) undergo training based on the Environmental Protection Agency's (EPA) I-BEAM program, which provides a structured method of performing inspections, in compliance with NADCA's standards and guidelines. The training and certification examination covers applicable building and Indoor Air Quality (IAQ) standards and codes, maintenance and housekeeping programs, diagnosing IAQ problems and reporting findings to building owners.

VENTILATION SYSTEM MOLD REMEDIATOR

DUCTZ professionals that hold the NADCA Ventilation System Mold Remediator (VSMR) certification have passed a rigorous examination that tests complete understanding of basic microbiological agents, how to perform project assessments, and the proper application of industry guidelines and standards. Every DUCTZ professional taking the VSMR certification examination must be ASCS-certified and must have attended the VSMR training class, or a recognized mold remediation and abatement training program.

The DUCTZ principles and practices documents (listed below) are designed to provide you with information to use in comparing commonly-used cleaning and restoration techniques for HVAC Systems. These documents are intended to be used as informational material only, not a scope of work.

Contact a DUCTZ professional to obtain more information, or to obtain a scope of work for your commercial, industrial or residential project.

Customer and Contractor Communications

Heating, ventilation and air conditioning (HVAC) system restoration contractors and duct cleaning contractors vary in their level of knowledge of Indoor Air Quality (IAQ); therefore, an assessment of a contractor's previous work experience can reduce the potential for improper planning and improperly executed services. To ensure a well-run project, it is imperative to clearly communicate the scope of work, project estimations and project deliverables.

The National Air Duct Cleaners Association (NADCA) has produced a standard entitled "Assessment Cleaning and Restoration of Mechanical Systems ACR2006" (The Standard). This is a performance assurance standard which can be used to determine a duct cleaning contractor's depth of knowledge, performance and execution. Properly used, the standard can firm up the level of communication between both the duct-cleaning contractor and the customer. The contractor must thoroughly understand the scope of the entire project. The standard allows a professional relationship to form between the parties, laying the foundation toward conducting and completing a successful project. The Air Conditioning Contractors Association (ACCA) created the American National Service Institute (ANSI) level standard known as the ACCA System Cleanliness Standard. This procedural standard has been very helpful to residential customers in assuring that proper steps are taken to protect their home or office throughout the entire cleaning process.

A duct cleaner's primary concern is to properly and thoroughly clean the air duct system safely and effectively, optimizing the efficiency of the HVAC system. The customer's knowledge of duct cleaning and IAQ analysis is helpful in creating and maintaining a smooth working relationship. During the initial project assessment, a clear understanding of the cleaning contractor's responsibilities must be established.

A qualified HVAC system restoration contractor can provide the customer or client with valuable information in accessing the system, project coordination, knowledge of similar systems, available techniques, and development of structured scopes, product knowledge and a wide variety of other topics. More importantly, addressing concerns such as the physiological and psychological impacts the duct cleaning project may have on employees are points at which a duct cleaner's experience and knowledge can be valuable to a well-run job. Many of these issues should be discussed before a project is scoped or contracted.

Project Review

Duct cleaning projects are designed to establish proper indoor air quality and optimize the efficiency of the heating, ventilation, and air conditioning (HVAC) system. Project length can vary from a few hours to six months or more, depending on the size, scope and severity of the project area. Project scopes are written by industrial hygienists, customers, indoor air quality (IAQ) consultants, duct cleaners, general contractors, or any number of other trade professionals. Even with an outlined scope of work, an HVAC duct-cleaning contractor's responsibility is to always use source removal during the cleaning process. The project scope document must contain standard language which confirms that the duct cleaner has removed all particulate. Document standards take particulate removal one step further and provide the client and duct cleaner with a verifiable test that can be conducted immediately after the cleaning process. Document standards are also a tool that can be used as a guide during the initial project review.

The entire project runs best when an in-depth review is conducted by the customer and contractor. Together, the customer and contractor determine the expectations of the project and outline the achievable results. Proper on-site preparation and evaluation must be conducted to ensure the health and well-being of the building occupants.

During the review process for commercial projects, it is important to:

• Review commercial blueprints (In the event blueprints are not available, be prepared to conduct extensive preliminary research)
• Establish project timelines for the scope of work, schedules of building availability, and review of timeline restrictions
• Ensure all products to be used during the cleaning process are discussed, approved, and thoroughly understood by the customer prior to the start of the project
• Obtain and review Material Safety Data Sheets
• Arrange consultations with key people, such as site managers, supervisors, security and maintenance officials who are in charge of those areas, as well as the personnel affected by the project
• Review specific duct cleaning techniques with the customer
• Review all safety concerns of the customer, both cleaning and environmental
• Determine if the contractor is expected to work in close cooperation with an Environmental Consultant and if a method of establishing clear communication exists

Evaluating the Project

Successful heating, ventilation, and air conditioning (HVAC) system or duct cleaning projects can have beneficial results, such as reduced health risks for people and increased HVAC system performance. On the other hand, an unsuccessful HVAC or duct cleaning project can result in increased exposure to contaminants and possible mechanical system malfunctions.

To ensure a successful project, site preparation must be clearly defined from the beginning of the project. Site preparation is the process by which the contractor and customer cooperatively review and evaluate all aspects of the HVAC or duct cleaning process as it relates to the facility and its occupants and develop strategies for safe and effective management of the project.

Proper site evaluations must address the following:

• Occupant safety
• Containment strategies
• Cross-contamination assessment
• Security
• Building and fire safety
• Protecting the indoor furniture
• Protecting computers and other office equipment
• Specific building-related issues

DUCTZ professionals are certified, qualified and trained to conduct on-site evaluations and properly prepare the site before, during and after the scope of work is performed. A duct cleaner's work is primarily performed above the ceiling tiles or in the attic spaces. However, duct cleaning equipment found on-site is highly visible to building occupants. The general appearance of a duct cleaner's equipment is critical to proper site preparation, as it will have a strong impact on the perception of the contractor and the effectiveness of the project work. DUCTZ professionals use proprietary equipment that is well maintained and highly specialized to perform the job. DUCTZ professionals are well-versed in site preparation and effectively work with preferred partners to ensure the site preparation is conducted properly.

For a positive and significant impact on the efficiency, cost effectiveness, and safety of the project, work with a DUCTZ professional. DUCTZ professionals are certified, qualified and trained to do the job right the first time.

Furniture and Flooring

All furniture and flooring located in close proximity to the areas to be cleaned should be protected with a covering. When beginning work in a new site, the occupants of that area should be informed that protective coverings are used and that they should prepare the area accordingly. Whenever possible, furniture should be moved to allow technicians easier access to the work site. For increased productivity, it is helpful to temporarily relocate all fragile or breakable items. Flooring should be well protected. Some duct cleaning equipment is large and needs to be moved through the facility. Floor preparations can range from light coverings to plywood planking secured to the flooring for the duration of the project. Consult with the cleaning supervisor at the beginning of the project to determine whether all furniture and horizontal surfaces need to be physically wiped down after the day's work. Building occupants tend to place new emphasis on dirt found after a duct cleaning project begins.

Occupant Safety and Contaminant Protection

During the duct cleaning procedure, a primary concern must be the health, safety, and well-being of the facility's occupants. One of the reasons for having the HVAC and duct systems cleaned is to provide a clean, healthy environment for the people inside the facility. A duct cleaner's experience and training in the latest techniques is necessary to determine and correct any potential safety or protection problems which may arise during the remediation process. An IAQ Consultant should be contacted to address additional facility occupant health and safety concerns.

Occupant issues of concern:

• Have all occupants been informed in advance of the cleaning process and the start and stop dates?
• Has special attention been given to respiratory sufferers?
• Will the cleaning process be conducted after hours or while the building is occupied?
• Are components of the HVAC system such as blower wheels, supply or return grilles, and ductwork going to be removed throughout the facility during the cleaning process?
• What will the downtime be on the HVAC system and what is the amount of time the facility needs to return to optimum temperature and humidity after cooling or heating has been restored?
• Are there any occupants with high environmental sensitivity issues?
• If the occupants' workday is to continue during the process, how will large equipment and tools affect the movement and management of people?
• How will interrupted and/or modified security issues change normal safety guidelines in the facility?
• How will interrupted and/or modified fire safety issues change normal safety guidelines in the facility?
• Whenever communicating with building occupants, do so in writing. Unless specifically hired as an IAQ Consultant, the duct cleaner's responsibility is to ensure occupant safety with regard to the specific procedures involved in cleaning the HVAC system and duct network.

Containment Strategies

The particulate removed from a duct system is generally not considered a regulated waste. However, it is prudent to observe proper environmental containment strategies during all HVAC duct cleaning projects. The goal of any containment strategy is to move gross particulate and microbiological material in an orderly manner from the point of removal to the point of capture without cross-contaminating the indoor environment. Individual strategies may differ from one duct cleaner to another. During complex commercial cleaning projects, an experienced duct cleaner draws heavily on prior knowledge, expertise and training. DUCTZ professionals are certified, qualified and trained within containment strategies.

The type of equipment used by a duct cleaner has a strong influence on the containment strategy selection. For example, the strength of a negative pressure collection device will have direct bearing upon the length of ductwork which can be cleaned from a single hookup point. When you are analyzing containment strategies with a duct cleaner, expect specific answers to containment questions with examples of how the equipment is used.

Use the following questions to prepare containment strategies:

• Will a negative pressure collection device be used? Will the ductwork be kept under a negative pressure while cleaning is being performed? Will the collection device remain running to pull all airborne contaminants toward it?
• How powerful is the negative pressure collection device? Usually, this is rated by CFM; the amount of suction will have a direct effect on the length of duct which can be cleaned.
• Will the negative pressure collection device be located inside or outside the facility during the cleaning process? If located inside, does it have HEPA (High Efficiency Particle Air) filtration?
• What length of duct can be cleaned (based on height and width of the duct) before significant loss of negative pressure occurs within the system? (Commercial)
• Where is the starting and ending point of each work cycle's activity? (Commercial)
• In what direction will the particulate be moved and how will it be captured?
• Will supply and return registers be sealed or removed, and has cross-contamination during the cleaning process been considered?
• Has the specific cleaning strategy been used before and in which verifiable projects?
• Is the proposed cleaning strategy counterproductive, by adding unnecessary labor or product to the project?
• Does the strategy consider the client's existing safety plans?
• What is the facility protection plan for contaminated equipment in both movement and breakdown?
• Is a system in place for all aspects of containment during the cleaning process? Without a clear understanding between the customer and contractor about particulate movement and containment, the project relies solely on the cleaning technician's best judgment.

Computers, Copiers, and Other Electronic Office Equipment

During site preparation, special attention should be given to all electronic equipment throughout the facility. A DUCTZ professional works in close proximity with highly sensitive equipment; in some cases, directly above the equipment. Additionally, water is used when cleaning HVAC coils, therefore additional measures are taken to protect the equipment.

To prepare electronic equipment for the cleaning process, it is important to first determine if the equipment can temporarily be moved to a safe location. If moving the equipment is not an option, then the equipment must be covered. Avoid covering electronic equipment with plastic or heat-restrictive coverings unless the equipment is shut down during cleaning. DUCTZ professionals make sure the user of the equipment is notified about the cleaning conducted in their work area.

Professionally Designed and Constructed Cleaning Equipment

The condition of an HVAC duct cleaner's equipment is a direct indicator of the level of professionalism a customer can expect on a project. Therefore, customers should always perform a hygiene/integrity inspection on all equipment brought onto the job site. Equipment must be in good working condition at all times. "Homemade" equipment or equipment built "in-house" can be an area of concern. Whenever possible, a duct cleaner who uses professionally designed and constructed equipment with a proven track record should be selected. The duct cleaning industry requires that equipment which cleans contaminants from a duct system is strictly filtered and maintained to prevent cross-contamination. There should be no hesitation in questioning any piece of equipment brought into a facility. The NADCA Standard specifically addresses equipment-related issues.

When performing a hygiene/integrity inspection of a duct cleaner's equipment, take the following items into consideration:

• Vacuum equipment must be clean and cabinets must fit well - improperly fitted seams with leaky or broken gaskets are a potential contamination problem to the indoor environment
• All vacuums and collection units should have new pre-filters in place
• Dents or cracks in the equipment that could cause performance issues
• Loose wires or switches that could cause sparks, or circuit interruptions
• Broken gauges
• All equipment must be sealed when entering the facility
• When a project is starting, all equipment must be completely cleaned, inside and out before being brought into the work environment
• Vacuum hoses must be in good condition, free from holes, tears, or leaks
• Air compressors used inside the facility must be free from oil leakage
• All wheels on rolling equipment must function properly so that flooring will not be harmed when equipment is transported throughout the facility

Equipment which fails to meet these minimum requirements should prompt further review of the cleaning process and the contractor. DUCTZ professionals strictly adhere to National Air Duct Cleaners Association (NADCA) standards and are certified, qualified and trained in the proper selection, maintenance and use of cleaning equipment.

Building Safety and Fire Policies

Proper duct cleaning requires that the customer and the duct cleaner understand the safety and fire procedures of a facility. Most commercial HVAC systems have alarms built into the ductwork which are designed to detect smoke and heat. These systems must be bypassed during the cleaning procedure to prevent false alarms and damage to the alarm components. All concerned parties, including the fire department and facility security services, must be made aware that normal fire and safety policies are altered during the cleaning project. All alarms need to be verified for operation after each work period.

Cross-Contamination Evaluation

During site preparation, a cross-contamination evaluation is prepared. This evaluation takes into consideration the various ways that particulate and microbial contaminants can enter the indoor environment during the cleaning process. Once the evaluation is complete, engineering controls are put in place to prevent cross contamination.

Some examples of commonly used engineering controls are:

• Containment barriers that restrict contaminants from exiting the work area and entering a clean area
• The use of air scrubbers to constantly filter the air within the work area
• The use of HEPA-filtered vacuums and collection devices to prevent the escape of particulate into the indoor environment
• Drop cloths and plastic sheeting to protect building contents

Cleaning techniques vary greatly from one duct cleaner to another, and the potential for environmental cross-contamination will also vary depending on the procedures being used. That is why the "Source Removal Methods" recommended by NADCA are adhered to. HEPA-filtered collection units are connected to the duct system to capture debris that is dislodged from within the duct system. If strict Engineering Controls are not put into place before cleaning starts, cross contamination will accrue, and lead to greater problems. Once a facility has been contaminated, an assessment is needed to determine the level of cleanliness of the indoor environment, and if a cleaning of all interior surfaces is necessary. Contamination issues are specifically addressed in the source document.

Security

Along with protecting the Indoor Air Quality (IAQ) of the facility, the duct cleaner is tasked to address unusual security conditions. Projects conducted during off or unusual hours will require changes in normal security to a building. Alarm systems and companies need to be notified well in advance. Security teams on larger locations need to be advised that outside doors and windows may be opened. In general, the normal facility security for that work area will be altered.

Specific and Unique Building-Related Items

The experience of a duct cleaner becomes far more important as specific and unique projects arise. If the facility has special requirements, it becomes essential to have a contractor who can draw from a wide variety of previous successful projects. It is the client's responsibility to evaluate and compare a number of duct cleaners and their techniques to determine which will work best in their situation.

Professionally Designed and Constructed Cleaning Equipment

There are a few pieces of equipment which are specific to the industry:

• HEPA-filtered collection device or collection units
• High-pressure air compressors
• HEPA-filtered vacuums
• Airless paint sprayers for application of coatings
• Mechanical brushing systems
• Pneumatic agitation equipment

This equipment will determine, to a large degree, how the cleaning project is conducted. When contracting with a reputable cleaning firm, ensure that some form of this industry-specific equipment is used. Always verify that the equipment is in good condition.

Negative Pressure Collection Device or Collection Unit

"Negative pressure collection device" or "collection device" are the terms designating the mechanism used to create a negative, or reverse airflow within the ductwork with sufficient velocity to prevent cross-contamination during the cleaning process. This unit should always be HEPA-filtered when located within the facility. These HEPA filters must have a D.O.P. certification serial number indicating that they have been certified by a third-party testing agency.

The collection device can be used during the cleaning process in a number of ways. If the duct size is small enough or short enough, the unit may be capable of creating enough velocity to draw all the loose particulate through the duct system. This technique is widely used in the residential arena. Another technique will use the device to generate an overall negative pressure while the system is being cleaned with contact vacuums or brushing and air sweeping. The duct cleaner is responsible for maintaining sufficient negative pressure within the duct system to prevent any possibility of cross-contamination.

The two main categories of this type of equipment are truck-mounted units and portable units. Both types have their place and are used widely throughout the country.

Air Compressor or Some Form of High Pressure Supply

Many of the tools and devices which are used are pneumatically powered. This requires the use of large amounts of air pressure to be supplied to these tools. The most common method of supplying this pressure is through an air compressor. Gasoline-operated compressors must always be located outside the facility, with precautions taken during site preparation to prevent exhaust fumes from entering the facility. Electric compressors can be located within the facility during the cleaning process. A third type of pressure supply used in the industry is dry nitrogen gas. Nitrogen is capable of reaching much higher pressures and can be more effective with various tools. Generally, expect to see some form of compressed air systems on any duct cleaning project.

HEPA-Filtered Contact Vacuums and Wet Vacuums

Contact vacuums are commonly used by duct cleaners for a variety of tasks. Expect to see this type of vacuum on location. HEPA filtration is an absolute must on these vacuums, especially when the wet vacuums are being used to clean microbiological contaminants from the drain pan and evaporator coil area within the facility. The duct cleaner must be able to demonstrate exactly how the vacuum is being filtered. This is important because many wet vacuums are not manufactured with HEPA filtration, and this equipment may be located within the facility during the cleaning project.

Airless Paint Sprayers for Application of Coatings

Airless paint sprayers are another tool in the duct cleaner's arsenal. This tool is used when the duct cleaner has been contracted to either re-coat the ducts interior insulation or to apply a coating within the HVAC unit.

Cleaning Methodologies

There are several methods and combinations of methods which are used regularly to clean HVAC and duct systems. There is no regulatory endorsement of any specific method as long as that method or combination of methods will achieve the levels of cleanliness required by each Standard. Each cleaning method has its strong and weak points. One factor affecting cleaning methodologies is the geographical location of the project. Regional climates are a general divider of techniques used in the HVAC duct cleaning industry. The two climate regions are high and low humidity areas. High humidity regions can cause severe buildup of microbial growth, mildew, yeasts, and bacteria. These buildups require more aggressive cleaning techniques when addressing the HVAC unit itself.

There are cleaning methods that have been used successfully for more than fifty years with little or no change in the technology. The method selected for cleaning a facility lies with the cleaning contractor. More often then not, the customer does not have the experience or the technical knowledge to make these decisions. It is the duct cleaner's responsibility to suggest and explain the best cleaning methods available for use while addressing the well being of the indoor environment.

Use of Negative Pressure Collection Unit

The negative pressure collection unit is perhaps the most commonly used and recognized piece of equipment in HVAC duct cleaning. For many firms this one piece of equipment is the axle around which all cleaning techniques revolve. The main purpose for the collection unit is to place the duct system under a negative pressure, so that the debris that is removed from the interior surface of the duct can be safely conveyed to the collection unit.

Although ducts can be cleaned in many ways, cleaning a system without a collection device can cause:

• Improper movement or removal of particulate
• Cross-contamination of facility
• Increased labor and project length
• To prevent any possibility of particulates re-entering the indoor environment

Air Washing/Sweeping

Air washing and sweeping are methods used to dislodge particulate from the inside walls of the duct. They are all, by definition, a mechanical means of agitating the ductwork's interior surface, loosening debris which has accumulated on the surface of the duct walls. These methods are rarely used alone and are normally used in conjunction with a negative pressure collection device. These techniques will vary greatly according to the type of duct being cleaned. Metallic ducts with no internal lining can be cleaned quite thoroughly and easily with aggressive cleaning methods. Caution must always be used, however, when using any mechanical agitation on fiberglass products. The mechanical agitation of ductwork is widely accepted as one of the essential methods of duct cleaning.

Mechanical Brushing

The term "brushing" is exactly what the name implies - the duct cleaner will use this technique when trying to get the system as clean as possible without washing or hand-wiping. The duct cleaner may employ a wide variety of brush types depending upon the type of duct to be cleaned and the type of contaminant present. Some may be attached to automatic rotating heads which spin inside the duct system, dislodging debris. These brushes are either pneumatic (air pressure) or cable-driven.

No standards currently exist to determine the effects of different types of brushes and bristles on various duct surfaces. It is accepted that metal ductwork with no internal liner can withstand very aggressive brushing techniques. Fiberglass liner and duct board rely more upon the individual cleaning company's professionalism and experience with the product, but can be cleaned successfully using the same type of techniques. The brushing technique is an important item to consider when contracting with a cleaning firm. Air washing alone may not always enable the duct cleaner to achieve the cleanliness levels set by the Standard.

Pneumatic Agitation Systems

Pneumatic agitation tools are usually air nozzles or rubber tubing powered by high-pressure compressed air. Some are used to air wash a duct system after mechanical brushing has been performed, and some are aggressive enough to use as an agitation device. As with any tool, it is left to the cleaning contractor's expertise to determine the proper tool for the application.

Hand or Contact Vacuuming

Hand or contact vacuuming is another technique used by duct cleaners. Brushes are attached to extension wands and used by technicians to physically brush the surface inside the HVAC unit. Contact vacuums lift particulate from a porous duct surface or HVAC surface in one motion. All hand vacuums must follow strict procedures for filtration if located inside the facility or home. Contact vacuuming is a popular method used on duct board ducts, internally-insulated ducts or thermal insulation located within an HVAC unit.

Hand vacuums are also used to vacuum off evaporator coils before a Type II coil cleaning, and can be used as wet vacuums to clean drain pan sludge. Most hand vacuums provide the cleaning contractor with versatility in unusual circumstances.

Access and Entry

Gaining access into the duct network can be handled in several ways. Specific hand tools are made to create square and centered access holes which leave safe entry ports for future inspection.

Two common closure methods of these access holes are the use of pre-fabricated access doors, which allow simple future access, and the use of access plates, which are permanently attached and sealed onto the ductwork.

Access doors and plates both require the penetration of the duct and insulation. Insulation should be handled in accordance with the North American Insulation Manufacturers Association (NAIMA) guideline for cleaning fibrous glass insulation or duct systems to prevent future condensation problems from occurring.

Contractors can identify the types of access and entry that are used throughout the cleaning project and inform the customer of special conditions requiring alternate methods. The opening and closure methods used on duct board will differ greatly from the methods used on metallic ductwork. Projects having several types of ductwork must be analyzed for all opening and closure methods to be used.

Improperly sealed openings can create duct leakage, future IAQ problems and air flow imbalance. All access doors must be installed according to manufacturer's specifications and all access plates should be sealed with a UL181 mastic and be in accordance with Sheet Metal and Air Conditioning Contractors' National Association (SMACNA) standards.

Breakdown and Cleanup

Breakdown and cleanup are issues which may have a strong psychological impact on a cleaning project. The duct cleaner is responsible for making sure that all equipment is removed from a facility in a fashion that will not cause cross-contamination. This means that negative pressure collection devices, or collection devices, which were located within the facility, should not be opened, exposing contaminants to the indoor environment without proper procedures being in place. The same holds true for all other equipment and tools the contractor uses during the process.

Cleanup of the facility can be addressed in two ways: total breakdown and cleanup directly after completion required in short-term projects; and cleanup on a shift by shift basis, or as movement progresses through the facility, which is necessary on long-term projects. When contracting a duct cleaner, be certain to address the level of cleanup expected at the end of each cleaning cycle.

Some projects require extensive cleaning of all horizontal surfaces after an area has been completed. This is due to the fact that occupants of the facility tend to think any existing debris on a horizontal surface could have been a direct result of the cleaning process, raising unnecessary alarm. Well-coordinated projects will have normal cleaning of the facility scheduled at the completion of the duct cleaning. A quality HVAC duct cleaning company will have a strong system in place to clean up a facility after the work has been completed. A leading indicator of the quality of breakdown and cleanup can be assessed during the initial site preparation. One of the items to address is where the dirt and debris removed from the facility is discarded.

Surface Treatments

In the past, the issue of using any surface treatment as a method of cleaning ducts has been controversial. Surface treatments, when used alone, will not provide a clean duct. Source removal of the organic and inert contaminants within the duct system must be the primary method utilized to perform HVAC duct system cleaning in accordance with national standards. One of the reasons for much of the controversy was created by the constant application of non-EPA registered products to duct surfaces. A second reason for debate was the general misapplication of all these surface treatments. In theory, the application of a coating to a fiberglass duct surface which is beginning to degrade has great appeal. The creation of a new interior surface to the duct system without the replacement of that system can greatly offset replacement costs.

One of the factors which will affect a customer's decision whether to use these products is the location of the project. Areas of the country which have high humidity tend to rely on surface treatments far more often than low humidity regions. The difference between the two regions is the ability for microbiological contaminants to live and grow within the duct system. Most surface treatments have some level of biological control with some specifically designed to eliminate or reduce these types of contaminants. When considering the application of surface treatments it is essential to secure the EPA registration number for that specific product. NFPA 90a, NFPA 90b and Underwriters Laboratories UL181 should also be consulted during the approval process.

It is generally accepted that surface treatments are employed after the ducts have undergone a thorough source-removal process. The use of these surface treatments alone, on non-cleaned surfaces, should never be accepted as a method of cleaning ducts. Surface treatments can solve many customer concerns, such as fiberglass surface integrity problems and an alternate method of microbiological control. Most surface treatments fall into two categories: coatings and biocide treatments.

Surface Repair Coatings

Many surface repair coatings are used to aid in complex problems that emerge when restoring fiberglass-lined ductwork and duct board-lined ducts. All coatings must have proper registration with the EPA for specific use on the inside of ductwork surfaces. Fiberglass insulation within the HVAC unit is the most likely surface to require coating. An assessment of the integrity of the fiberglass liner or ducts is generally made to determine whether coating or replacement is necessary. Products that claim to inhibit or eliminate microbiological growth must be registered under applicable state or federal pesticide applicator business licensing regulations.

Biocide Applications

The second type of surface treatment used in the cleaning of duct systems is a liquid biocide applied to all duct interior surfaces. These products should only be used to resolve a specific microbial issue. These treatments are also applied to clean ducts as a preventive maintenance measure. Any biocide used within an HVAC system is required to carry EPA registration for the specific applications for which they are used. Manufacturer's specifications must be strictly followed by the contractor when mixing and applying these products. DUCTZ applicators of products that inhibit or eliminate microbiological growth must be registered under applicable state or federal pesticide applicator business licensing regulations.

Liners and Barriers

Barriers are used as a surface treatment to significantly reduce the absorption and retention of moisture by porous surfaces, thereby minimizing future microbiological growth. Surface barriers are applied only after the ducts have undergone a thorough source removal process. Liners and barriers provide an easily cleaned surface, which aids in long-term maintenance of the unit.

Teardown and Cleanup

The duct cleaner is responsible for making sure that all equipment is removed from a facility in a fashion that will not cause particle migration. This means that HEPA collection devices which were located within the facility should not be opened, exposing gathered particulate to the indoor environment without proper procedures being in place. The same holds true for all other equipment and tools the contractor uses during the process.

A quality HVAC duct cleaning company will have a strong system in place to clean up a facility after the work has been completed. A leading indicator of the quality of breakdown and cleanup can be assessed during the initial site preparation. One of the items to address is where the dirt and debris removed from the facility is discarded.

Verification and Cleanliness

Approving cleaning methods for a project means little without a verification program. Many times, if the client is uncomfortable about self-verification, a third party can be brought in to oversee the verification. Other methods may include; video, photo reports, and or a thorough walk through by the customer with the cleaning contractor.