Do Home Central Air System Need Cleaned
EPA 402-K-97-002, October 1997
On this page:
- Summary
- What Is Air Duct Cleaning?
- Deciding Whether or Not to Have Your Air Ducts Cleaned
- Suggestions for Choosing a Duct Cleaning Service Provider
- What to Expect of an Air Duct Cleaning Service Provider
- How to Decide if the Duct Cleaner Did a Thorough Chore
- How to Prevent Duct Contamination
- To Prevent Dirt from Entering the Arrangement
- To Prevent Ducts from Becoming Wet
- Unresolved Issues of Duct Cleaning
- Does duct cleaning prevent health problems?
- Are duct materials other than bare sheet metal ducts more likely to be contaminated with mold and other biological contaminants?
- Should chemic biocides exist practical to the inside of air ducts?
- Do sealants prevent the release of grit and dirt particles into the air?
- To Learn More than Virtually Indoor Air Quality
- To Learn More About Air Duct Cleaning
- Other Useful Resources
- Consumer Checklist
Summary
Noesis about air duct cleaning is in its early stages, so a blanket recommendation cannot be offered equally to whether you should have your air ducts in your home cleaned. The U.S. Environmental Protection Agency (EPA) urges y'all to read this document in information technology entirety as it provides of import data on the subject.
Duct cleaning has never been shown to actually forestall health problems. Neither do studies conclusively demonstrate that particle (e.m., dust) levels in homes increment considering of dirty air ducts. This is because much of the clay in air ducts adheres to duct surfaces and does non necessarily enter the living infinite. Information technology is important to keep in mind that dirty air ducts are only one of many possible sources of particles that are present in homes. Pollutants that enter the habitation both from outdoors and indoor activities such equally cooking, cleaning, smoking, or but moving around can cause greater exposure to contaminants than dingy air ducts. Moreover, there is no prove that a light corporeality of household grit or other particulate matter in air ducts poses any run a risk to your wellness.
You should consider having the air ducts in your home cleaned if:
There is substantial visible mold growth within hard surface (due east.g., sheet metal) ducts or on other components of your heating and cooling organisation. There are several important points to empathize apropos mold detection in heating and cooling systems:
- Many sections of your heating and cooling system may not exist attainable for a visible inspection, so ask the service provider to bear witness you whatsoever mold they say exists.
- You should exist aware that although a substance may wait similar mold, a positive determination of whether it is mold or not can be made simply past an adept and may crave laboratory assay for final confirmation. For about $50, some microbiology laboratories can tell you whether a sample sent to them on a clear strip of viscous household tape is mold or merely a substance that resembles information technology.
- If y'all accept insulated air ducts and the insulation gets wet or moldy it cannot be effectively cleaned and should be removed and replaced.
- If the atmospheric condition causing the mold growth in the first identify are not corrected, mold growth will recur.
Ducts are infested with vermin, eastward.g. (rodents or insects).
Ducts are clogged with excessive amounts of dust and debris and/or particles are actually released into the home from your supply registers.
If whatever of the conditions identified in a higher place exists, it usually suggests one or more underlying causes. Prior to any cleaning, retrofitting, or replacing of your ducts, the cause or causes must exist corrected or else the problem will likely recur.
Some inquiry suggests that cleaning heating and cooling system components (e.g., cooling coils, fans and rut exchangers) may ameliorate the efficiency of your arrangement, resulting in a longer operating life, as well as some energy and maintenance cost savings. However, little bear witness exists that cleaning only the ducts will improve the efficiency of the arrangement.
You may consider having your air ducts cleaned merely because it seems logical that air ducts will become dirty over time and should be occasionally cleaned. Provided that the cleaning is done properly, no evidence suggests that such cleaning would be detrimental. EPA does not recommend that the air ducts be cleaned routinely, merely only equally needed. EPA does, nonetheless, recommend that if you accept a fuel burning furnace, stove or fireplace, they exist inspected for proper operation and serviced before each heating season to protect confronting carbon monoxide poisoning.
If yous practise determine to have your air ducts cleaned, take the same consumer precautions you lot normally would in assessing the service provider's competence and reliability.
Air duct cleaning service providers may tell you that they need to utilise chemic biocide to the inside of your ducts as a means to kill bacteria (germs) and fungi (mold) and prevent futurity biological growth. They may also suggest the application of a "sealant" to prevent dust and clay particles from being released into the air or to seal air leaks. Yous should fully understand the pros and cons of permitting application of chemical biocides or sealants. While the targeted use of chemic biocides and sealants may exist appropriate under specific circumstances, inquiry has not demonstrated their effectiveness in duct cleaning or their potential adverse health effects. No chemical biocides are currently registered past EPA for utilize in internally-insulated air duct systems (meet Should chemical biocides be applied to the within of air ducts?).
Whether or not you decide to have the air ducts in your home cleaned, preventing water and dirt from inbound the organization is the most effective way to prevent contamination (see How to Forestall Duct Contagion).
What is Air Duct Cleaning?
Nigh people are now aware that indoor air pollution is an issue of growing concern and increased visibility. Many companies are marketing products and services intended to improve the quality of your indoor air. You have probably seen an advertizing, received a coupon in the post, or been approached directly past a company offering to clean your air ducts as a means of improving your home's indoor air quality. These services typically — but non ever — range in cost from $450 to $1,000 per heating and cooling system, depending on:
the services offered
- the size of the arrangement to be cleaned
- system accessibility
- climatic region
- level of contamination
If y'all decide to take your heating and cooling arrangement cleaned, information technology important to make sure the service provider agrees to clean all components of the system and is qualified to do then.
Duct cleaning by and large refers to the cleaning of various heating and cooling system components of forced air systems, including the supply and render air ducts and registers, grilles and diffusers, heat exchangers heating and cooling coils, condensate drain pans (drip pans), fan motor and fan housing, and the air treatment unit housing (Come across diagram).
If not properly installed, maintained and operated, these components may become contaminated with particles of dust, pollen or other debris. If wet is present, the potential for microbiological growth (e.one thousand., mold) is increased and spores from such growth may be released into the abode's living space. Some of these contaminants may crusade allergic reactions or other symptoms in people if they are exposed to them. If you decide to have your heating and cooling system cleaned, information technology is important to make sure the service provider agrees to clean all components of the system and is qualified to practise so. Failure to clean a component of a contaminated arrangement tin consequence in re-contagion of the entire organization, thus negating any potential benefits. Methods of duct cleaning vary, although standards have been established by industry associations concerned with air duct cleaning. Typically, a service provider volition use specialized tools to dislodge dirt and other droppings in ducts, and then vacuum them out with a high-powered vacuum cleaner.
In addition, the service provider may propose applying chemical biocides, designed to kill microbiological contaminants, to the inside of the duct work and to other system components. Some service providers may also suggest applying chemical treatments (sealants or other encapsulants) to encapsulate or comprehend the inside surfaces of the air ducts and equipment housings considering they believe information technology will control mold growth or forbid the release of dirt particles or fibers from ducts. These practices have yet to be fully researched and you should be fully informed earlier deciding to let the use of biocides or chemical treatments in your air ducts. They should but be applied, if at all, after the organization has been properly cleaned of all visible grit or droppings.
Notation: Use of sealants to encapsulate the inside surfaces of ducts is a dissimilar do than sealing duct air leaks. Sealing duct air leaks can help save free energy on heating and cooling bills. For more than information, run across EPA's Energy Star website.
Deciding Whether or Not to Accept Your Air Ducts Cleaned
Cognition most the potential benefits and possible bug of air duct cleaning is limited. Since conditions in every domicile are different, it is impossible to generalize virtually whether or not air duct cleaning in your habitation would be beneficial.
If no i in your household suffers from allergies or unexplained symptoms or illnesses and if, after a visual inspection of the inside of the ducts, you come across no indication that your air ducts are contaminated with big deposits of dust or mold (no musty odor or visible mold growth), having your air ducts cleaned is probably unnecessary. It is normal for the render registers to get dusty every bit dust-laden air is pulled through the grate. This does not point that your air ducts are contaminated with heavy deposits of dust or debris; the registers tin be easily vacuumed or removed and cleaned.
On the other mitt, if family members are experiencing unusual or unexplained symptoms or illnesses that you think might be related to your dwelling environment, you should hash out the situation with your doctor. EPA has published the following publications for guidance on identifying possible indoor air quality issues and ways to forbid or gear up them.
- Indoor Air Quality: An Introduction for Wellness Professionals
- The Within Story: A Guide to Indoor Air Quality
Yous may consider having your air ducts cleaned only considering it seems logical that air ducts will get muddy over time and should occasionally be cleaned. While the debate about the value of periodic duct cleaning continues, no prove suggests that such cleaning would be detrimental, provided that it is done properly.
On the other hand, if a service provider fails to follow proper duct cleaning procedures, duct cleaning can cause indoor air problems. For example, an inadequate vacuum collection system can release more dust, dirt and other contaminants than if you had left the ducts alone. A careless or inadequately trained service provider tin can damage your ducts or heating and cooling system, perhaps increasing your heating and air conditioning costs or forcing you to undertake difficult and plush repairs or replacements.
You lot should consider having the air ducts in your abode cleaned if:
In that location is substantial visible mold growth inside difficult surface (east.thou., canvass metal) ducts or on other components of your heating and cooling organisation. There are several of import points to sympathize concerning mold detection in heating and cooling systems:
- Many sections of your heating and cooling system may not exist accessible for a visible inspection, so enquire the service provider to bear witness y'all any mold they say exists.
- Y'all should be aware that although a substance may wait like mold, a positive determination of whether it is mold or not can be made only by an expert and may require laboratory analysis for final confirmation. For about $50, some microbiology laboratories can tell you whether a sample sent to them on a clear strip of gluey household tape is mold or only a substance that resembles it.
- If yous have insulated air ducts and the insulation gets moisture or moldy it cannot be effectively cleaned and should exist removed and replaced.
- If the conditions causing the mold growth in the first place are not corrected, mold growth will recur.
Ducts are infested with vermin, e.g. (rodents or insects)
Ducts are clogged with excessive amounts of dust and debris and/or particles are actually released into the domicile from your supply registers.
Other Important Considerations
Duct cleaning has never been shown to really prevent health problems. Neither practice studies conclusively demonstrate that particle (due east.g., dust) levels in homes increment because of dirty air ducts or become down later on cleaning. This is because much of the dirt that may accrue inside air ducts adheres to duct surfaces and does not necessarily enter the living infinite. Information technology is important to keep in mind that dingy air ducts are simply ane of many possible sources of particles that are nowadays in homes. Pollutants that enter the dwelling both from outdoors and indoor activities such as cooking, cleaning, smoking, or just moving around can cause greater exposure to contaminants than dirty air ducts. Moreover, at that place is no prove that a lite corporeality of household dust or other particulate matter in air ducts poses whatsoever risk to health.
EPA does non recommend that air ducts be cleaned except on an as-needed footing because of the continuing doubt near the benefits of duct cleaning under most circumstances. EPA does, however, recommend that if y'all take a fuel burning furnace, stove, or fireplace, they be inspected for proper functioning and serviced before each heating flavour to protect confronting carbon monoxide poisoning. Some research as well suggests that cleaning dirty cooling coils, fans and heat exchangers can better the efficiency of heating and cooling systems. However, piddling bear witness exists to indicate that only cleaning the duct organisation will increase your system's efficiency.
If yous call up duct cleaning might be a good idea for your home, only you are not certain, talk to a professional. The company that services your heating and cooling system may be a good source of communication. You may also want to contact professional person duct cleaning service providers and ask them about the services they provide. Remember, they are trying to sell you a service, and then ask questions and insist on complete and knowledgeable answers.
Suggestions for Choosing a Duct Cleaning Service Provider
To find companies that provide duct cleaning services, check your Yellow Pages nether "duct cleaning" or contact the National Air Duct Cleaners Clan (NADCA) at the address and phone number in the information section located at the end of this guidance. Do not assume that all duct cleaning service providers are equally knowledgeable and responsible. Talk to at to the lowest degree three different service providers and get written estimates before deciding whether to have your ducts cleaned. When the service providers come up to your home, ask them to prove you lot the contagion that would justify having your ducts cleaned.
Practice non rent duct cleaners who make sweeping claims about the health benefits of duct cleaning — such claims are unsubstantiated. Exercise non hire duct cleaners who recommend duct cleaning as a routine part of your heating and cooling organization maintenance. You should besides exist wary of duct cleaners who claim to exist certified by EPA. Note: EPA neither establishes duct cleaning standards nor certifies, endorses, or approves duct cleaning companies.
Practice not allow the use of chemical biocides or chemical treatments unless yous fully understand the pros and the cons (See "Unresolved Issues of Duct Cleaning).
Check references to be certain other customers were satisfied and did not experience any issues with their heating and cooling system afterwards cleaning.
Contact your canton or city office of consumer affairs or local Better Business Bureau to determine if complaints accept been lodged confronting any of the companies you are considering.
Interview potential service providers to ensure:
- they are experienced in duct cleaning and have worked on systems like yours;
- they volition use procedures to protect you, your pets and your habitation from contamination; and
- they comply with NADCA's air duct cleaning standards and, if your ducts are constructed of fiber drinking glass duct lath or insulated internally with fiber glass duct liner, with the Northward American Insulation Manufacturers Clan'southward (NAIMA) recommendations.
Inquire the service provider whether they concur any relevant country licenses. As of 1996, the following states require air duct cleaners to hold special licenses: Arizona, Arkansas, California, Florida, Georgia, Michigan and Texas. Other states may require them equally well.
If the service provider charges by the hour, asking an estimate of the number of hours or days the chore will have, and find out whether in that location will be interruptions in the work. Make sure the duct cleaner y'all choose will provide a written understanding outlining the total toll and scope of the job earlier piece of work begins.
What to Expect From an Air Duct Cleaning Service Provider
If you cull to accept your ducts cleaned, the service provider should:
Open admission ports or doors to allow the entire system to exist cleaned and inspected.
Inspect the system before cleaning to be sure that at that place are no asbestos-containing materials (eastward.g., insulation, register boots, etc.) in the heating and cooling system. Asbestos-containing materials require specialized procedures and should not be disturbed or removed except by specially trained and equipped contractors.
Use vacuum equipment that exhausts particles outside of the home or utilize simply high-efficiency particle air (HEPA) vacuuming equipment if the vacuum exhausts inside the home.
Protect carpet and household furnishings during cleaning.
Apply well-controlled brushing of duct surfaces in conjunction with contact vacuum cleaning to dislodge dust and other particles.
Apply only soft-bristled brushes for fiberglass duct board and canvas metal ducts internally lined with fiberglass. (Although flex duct can also be cleaned using soft-bristled brushes, it can be more economical to simply supercede accessible flex duct.)
Have care to protect the duct piece of work, including sealing and re-insulating any admission holes the service provider may have made or used and then they are airtight.
Follow NADCA'due south standards for air duct cleaning and NAIMA'southward recommended do for ducts containing cobweb glass lining or constructed of fiber drinking glass duct board.
How to Determine if the Duct Cleaner Did A Thorough Task
A thorough visual inspection is the best way to verify the cleanliness of your heating and cooling organisation. Some service providers use remote photography to document conditions inside ducts. All portions of the arrangement should be visibly clean; you should not be able to observe any debris with the naked eye. Prove the Post-Cleaning Consumer Checklist to the service provider before the work begins. Later completing the job, ask the service provider to evidence yous each component of your organization to verify that the job was performed satisfactorily.
If yous respond "No" to any of the questions on the checklist, this may indicate a problem with the task. Ask your service provider to correct any deficiencies until you can respond "yes" to all the questions on the checklist.
| Post Cleaning Consumer Checklist | Yeah | No | |
|---|---|---|---|
| General | Did the service provider obtain access to and make clean the unabridged heating and cooling organisation, including ductwork and all components (drain pans, humidifiers, coils and fans)? | ||
| Has the service provider fairly demonstrated that duct work and plenums are clean? (Plenum is a space in which supply or return air is mixed or moves; can be duct, joist infinite, attic and clamber spaces, or wall crenel.) | |||
| Heating | Is the heat exchanger surface visibly clean? | ||
| Cooling Components | Are both sides of the cooling coil visibly clean? | ||
| If yous indicate a flashlight into the cooling coil, does low-cal shine through the other side? It should if the coil is clean. | |||
| Are the coil fins straight and evenly spaced (as opposed to existence bent over and smashed together)? | |||
| Is the coil drain pan completely clean and draining properly? | |||
| Blower | Are the blower blades clean and complimentary of oil and droppings? | ||
| Is the blower compartment free of visible dust or droppings? | |||
| Plenums | Is the render air plenum free of visible dust or debris? | ||
| Do filters fit properly and are they the proper efficiency as recommended past HVAC system manufacturer? | |||
| Is the supply air plenum (direct downstream of the air handling unit) free of moisture stains and contaminants? | |||
| Metallic Ducts | Are interior ductwork surfaces free of visible debris? (Select several sites at random in both the return and supply sides of the organisation.) | ||
| Fiber Glass | Is all fiber glass material in skilful condition (i.east., free of tears and abrasions; well adhered to underlying materials)? | ||
| Access Doors | Are newly installed access doors in sheet metal ducts attached with more than just duct tape (east.g., screws, rivets, mastic, etc.)? | ||
| With the system running, is air leakage through access doors or covers very slight or non-existent? | |||
| Air Vents | Have all registers, grilles and diffusers been firmly reattached to the walls, floors and/or ceilings? | ||
| Are the registers, grilles and diffusers visibly make clean? | |||
| Organisation Operation | Does the system function properly in both the heating and cooling modes after cleaning? | ||
How to Prevent Duct Contamination
Whether or not you decide to accept the air ducts in your habitation cleaned, committing to a practiced preventive maintenance plan is essential to minimize duct contagion.
To prevent dirt from inbound the system:
Use the highest efficiency air filter recommended past the manufacturer of your heating and cooling system.
Change filters regularly.
If your filters become clogged, alter them more frequently.
Exist certain yous do non have whatsoever missing filters and that air cannot bypass filters through gaps effectually the filter holder.
When having your heating and cooling organization maintained or checked for other reasons, be sure to ask the service provider to clean cooling coils and bleed pans.
During construction or renovation work that produces dust in your home, seal off supply and render registers and practice not operate the heating and cooling arrangement until after cleaning upwards the grit.
Remove grit and vacuum your domicile regularly. (Utilize a loftier efficiency vacuum (HEPA) cleaner or the highest efficiency filter numberless your vacuum cleaner tin accept. Vacuuming tin can increment the corporeality of grit in the air during and after vacuuming too as in your ducts).
If your heating system includes in-duct humidification equipment, be sure to operate and maintain the humidifier strictly every bit recommended past the manufacturer.
Whether of not you decide to have the air ducts in your home cleaned, committing to a good preventive maintenance program is essential to minimize duct contagion.
To preclude ducts from condign wet:
Moisture should not exist present in ducts. Decision-making moisture is the about effective way to prevent biological growth in air ducts.
Moisture can enter the duct system through leaks or if the system has been improperly installed or serviced. Enquiry suggests that condensation (which occurs when a surface temperature is lower than the dew point temperature of the surrounding air) on or virtually cooling coils of air conditioning units is a major cistron in moisture contamination of the arrangement. The presence of condensation or high relative humidity is an important indicator of the potential for mold growth on any type of duct. Controlling moisture can often exist difficult, merely hither are some steps you tin take:
Promptly and properly repair any leaks or water damage.
Pay item attention to cooling coils, which are designed to remove water from the air and can be a major source of moisture contamination of the system that tin can pb to mold growth. Make sure the condensate pan drains properly. The presence of substantial standing water and/or debris indicates a trouble requiring immediate attending. Check any insulation about cooling coils for wet spots.
Make sure ducts are properly sealed and insulated in all non-air-conditioned spaces (e.m., attics and crawl spaces). This will help to prevent moisture due to condensation from entering the system and is important to make the system work as intended. To prevent water condensation, the heating and cooling organization must be properly insulated.
If you are replacing your air workout system, make sure that the unit is the proper size for your needs and that all ducts are sealed at the joints. A unit that is too large volition cycle on and off frequently, resulting in poor moisture removal, particularly in areas with high humidity. Besides make sure that your new organisation is designed to manage condensation effectively.
Unresolved Issues of Duct Cleaning
Does duct cleaning prevent wellness problems?
The bottom line is: no 1 knows. At that place are examples of ducts that accept become badly contaminated with a variety of materials that may pose risks to your health. The duct organisation can serve equally a ways to distribute these contaminants throughout a domicile. In these cases, duct cleaning may make sense. Still, a calorie-free amount of household dust in your air ducts is normal. Duct cleaning is not considered to be a necessary part of yearly maintenance of your heating and cooling organisation, which consists of regular cleaning of drain pans and heating and cooling coils, regular filter changes and yearly inspections of heating equipment. Research continues in an effort to evaluate the potential benefits of air duct cleaning.
In the meantime
Brainwash yourself most duct cleaning past contacting some or all of the sources of information listed at the end of this publication and asking questions of potential service providers.
Are duct materials other than bare sheet metal ducts more likely to be contaminated with mold and other biological contaminants?
You lot may be familiar with air ducts that are synthetic of sheet metal. Yet, many mod residential air duct systems are synthetic of fiber glass duct lath or sheet metal ducts that are lined on the inside with fiber drinking glass duct liner. Since the early 1970's, a significant increase in the use of flexible duct, which generally is internally lined with plastic or another type of fabric, has occurred.
The use of insulated duct textile has increased due:
- to improved temperature control
- energy conservation
- reduced condensation
Internal insulation provides better acoustical (noise) control. Flexible duct is very low cost. These products are engineered specifically for use in ducts or as ducts themselves, and are tested in accordance with standards established by Underwriters Laboratories (UL), the American Society for Testing and Materials (ASTM), and the National Fire Protection Clan (NFPA). Many insulated duct systems take operated for years without supporting significant mold growth. Keeping them reasonably clean and dry is generally acceptable. However, in that location is substantial debate about whether porous insulation materials (e.grand., fiber glass) are more prone to microbial contamination than bare sheet metal ducts. If enough dirt and wet are permitted to enter the duct system, in that location may be no significant difference in the rate or extent of microbial growth in internally lined or blank sheet metal ducts. Nevertheless, treatment of mold contamination on bare sheet metal is much easier. Cleaning and treatment with an EPA-registered biocide are possible. Once fiberglass duct liner is contaminated with mold, cleaning is not sufficient to preclude re-growth and at that place are no EPA-registered biocides for the treatment of porous duct materials. EPA, NADCA and NAIMA all recommend the replacement of moisture or moldy cobweb glass duct material.
In the meantime
Experts practice agree that moisture should not be present in ducts and if moisture and dirt are present, the potential exists for biological contaminants to grow and be distributed throughout the home. Decision-making wet is the virtually effective way to forestall biological growth in all types of air ducts.
Right whatsoever h2o leaks or continuing water.
Remove standing h2o under cooling coils of air handling units by making certain that drain pans slope toward the bleed.
If humidifiers are used, they must be properly maintained.
Air handling units should be constructed so that maintenance personnel have easy, direct access to heat exchange components and drain pans for proper cleaning and maintenance.
Cobweb glass, or any other insulation textile that is wet or visibly moldy (or if an unacceptable scent is present) should be removed and replaced by a qualified heating and cooling arrangement contractor.
Steam cleaning and other methods involving moisture should not be used on any kind of duct work.
Should chemic biocides be practical to the inside of air ducts?
Air duct cleaning service providers may tell you that they demand to use a chemical biocide to the inside of your ducts to kill bacteria (germs) and fungi (mold), and prevent time to come biological growth. Some duct cleaning service providers may propose to introduce ozone to kill biological contaminants. Ozone is a highly reactive gas that is regulated in the outside air every bit a lung irritant. Still, at that place remains considerable controversy over the necessity and wisdom of introducing chemical biocides or ozone into the duct work.
Among the possible problems with biocide and ozone application in air ducts:
- Little inquiry has been conducted to demonstrate the effectiveness of most biocides and ozone when used inside ducts. Simply spraying or otherwise introducing these materials into the operating duct system may cause much of the material to be transported through the system and released into other areas of your dwelling house.
- Some people may react negatively to the biocide or ozone, causing adverse health reactions.
Chemical biocides are regulated by EPA under Federal pesticide law. A product must exist registered by EPA for a specific use before it can be legally used for that purpose. The specific use(southward) must appear on the pesticide (due east.g., biocide) characterization, forth with other important data. It is a violation of federal police force to use a pesticide product in any mode inconsistent with the label directions.
A small number of products are currently registered by EPA specifically for apply on the inside of bare sheet metal air ducts. A number of products are also registered for apply every bit sanitizers on difficult surfaces, which could include the interior of bare sheet metal ducts. While many such products may be used legally inside of unlined ducts if all label directions are followed, some of the directions on the label may exist inappropriate for use in ducts. For example, if the directions indicate "rinse with water", the added wet could stimulate mold growth.
All of the products discussed higher up are registered solely for the purpose of sanitizing the shine surfaces of unlined (blank) sheet metal ducts. No products are currently registered every bit biocides for use on fiber glass duct board or cobweb drinking glass lined ducts, and so it is of import to decide if sections of your system contain these materials before permitting the awarding of any biocide.
In the meantime
Before allowing a service provider to apply a chemical biocide in your duct piece of work, the service provider should:
Demonstrate visible evidence of microbial growth in your duct work. Some service providers may effort to convince you that your air ducts are contaminated by demonstrating that the microorganisms found in your home abound on a settling plate (i.due east., petri dish). This is inappropriate. Some microorganisms are e'er present in the air, and some growth on a settling plate is normal. As noted earlier, only an expert tin positively place a substance as biological growth and lab assay may exist required for final confirmation. Other testing methods are non reliable.
Explain why biological growth cannot be removed by concrete means, such as brushing, and further growth prevented by decision-making moisture.
If you make up one's mind to permit the use of a biocide, the service provider should:
Show you the biocide characterization, which volition describe its range of canonical uses.
Utilize the biocide only to un-insulated areas of the duct system after proper cleaning, if necessary to reduce the chances for re-growth of mold.
Always use the product strictly according to its label instructions.
While some low toxicity products may be legally applied while occupants of the home are present, you may wish to consider leaving the premises while the biocide is being applied as an added precaution.
Practise sealants prevent the release of dust and dirt particles into the air?
Manufacturers of products marketed to coat and encapsulate duct surfaces merits that these sealants prevent dust and dirt particles inside air ducts from beingness released into the air. Every bit with biocides, a sealant is often applied by spraying it into the operating duct organization. Laboratory tests indicate that materials introduced in this manner tend not to completely coat the duct surface. Application of sealants may too impact the acoustical (noise) and fire retarding characteristics of fiber glass lined or constructed ducts and may invalidate the manufacturer'due south warranty.
Questions about the safety, effectiveness and overall desirability of sealants remain. For example, footling is known about the potential toxicity of these products under typical utilise conditions or in the event they take hold of burn down.
In addition, sealants accept yet to exist evaluated for their resistance to deterioration over time which could add together particles to the duct air.
In the meantime
Most organizations concerned with duct cleaning, including EPA, NADCA, NAIMA and the Sheet Metal and Air Workout Contractors' National Clan (SMACNA) exercise not currently recommend the routine utilize of sealants to encapsulate contaminants in any type of duct. Instances when the use of sealants to encapsulate the duct surfaces may be appropriate include the repair of damaged fiber glass insulation or when combating fire damage within ducts. Sealants should never exist used on wet duct liner, to encompass actively growing mold, or to cover debris in the ducts, and should but be practical later cleaning co-ordinate to NADCA or other advisable guidelines or standards.
To Learn More than About Indoor Air Quality
U.S. Environmental Protection Agency
Part of Radiation and Indoor Air
Indoor Environments Sectionalization (6609J)
1200 Pennsylvania Avenue, North.West.
Washington, DC 20460
The post-obit EPA publications are available on this web site, some can be ordered from NSCEP. (see besides: Publications and Resource)
- The Inside Story: A Guide to Indoor Air Quality
- Indoor Air Pollution: An Introduction for Health Professionals
- Guide to Air Cleaners in the Home
- Ozone Generators that are Sold as Air Cleaners
To Learn More About Air Duct Cleaning
National Air Duct Cleaners Association (NADCA)
1120 Route 73, Suite 200
Mt. Laurel, NJ 08054
Phone: (855) GO-NADCA • (856) 380-6810
E-mail: info@nadca.com
Website: NADCA
Observe a NADCA professional person duct cleaner almost yous.
North American Insulation Manufacturers Association (NAIMA)
44 Canal Middle Plaza, Suite 310, Alexandria, VA 22314
Phone: (703) 684-0084
Website: NAIMA
Website: NAIMA Member Company List
"Cleaning Fibrous Glass Insulated Air Duct Systems; Recommended Practice", NAIMA Pub. No. AH122, 40 pages (Cost is $7.50 for a printed version, no free copies available.)
Other Useful Resources
For a free listing of state consumer protection offices:
State Consumer Protection Offices
For more information on biocides:
Antimicrobial Data Hotline
Phone: (703) 308-0127 / Fax: (703) 308-6467
Monday-Friday eight:00 AM - 5:00 PM EST
E-mail: Info_Antimicrobial@epa.gov
Website: Regulating Antimicrobial Pesticides
The Antimicrobials Information Hotline provides answers to questions concerning current antimicrobial issues (disinfectants, fungicides, others) regulated by the pesticide law, rules and regulations. These comprehend estimation laws, rules and regulations, and registration and re-registration of antimicrobial chemicals and products. The Hotline also provide data health & safety problems on registered antimicrobial products, product characterization and the proper and safe use of these antimicrobial products.
Consumer Checklist
Acquire as much as possible about air duct cleaning before you determine to take your ducts cleaned by reading this guidance and contacting the sources of data provided.
Consider other possible sources of indoor air pollution first if you suspect an indoor air quality trouble exists in your home.
Have your air ducts cleaned if they are visibly contaminated with substantial mold growth, pests or vermin, or are clogged with substantial deposits of dust or debris.
Ask the service provider to show you any mold or other biological contamination they say exists. Get laboratory confirmation of mold growth or decide to rely on your own judgment and common sense in evaluating apparent mold growth.
Get estimates from at to the lowest degree three service providers.
Bank check references.
Ask the service provider whether he/she holds any relevant state licenses. As of 1996, the post-obit states require air duct cleaners to hold special licenses: Arizona, Arkansas, California, Florida, Georgia, Michigan and Texas. Other states may also crave licenses.
Insist that the service provider requite yous knowledgeable and consummate answers to your questions.
Find out whether your ducts are made of sheet metal, flex duct, or constructed of fiber drinking glass duct board or lined with cobweb drinking glass since the methods of cleaning vary depending on duct type. Remember, a combination of these elements may be present.
Permit the application of biocides in your ducts just if necessary to control mold growth and only later assuring yourself that the product will exist practical strictly according to characterization directions. As a precaution, you lot and your pets should leave the bounds during application.
Practise non allow the use of sealants except under unusual circumstances where other alternatives are non viable.
Commit to a preventive maintenance program of yearly inspections of your heating and cooling system, regular filter changes, and steps to prevent moisture contagion.
Source: https://www.epa.gov/indoor-air-quality-iaq/should-you-have-air-ducts-your-home-cleaned
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