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ASBESTOS HVAC DUCTS - Asbestos Materials On or In Heating and Cooling Duct Work AirCondAPedia © How to Inspect the Central Air Conditioning, Cooling System, or Heating System Enter your search terms Submit search form   Search This Website - InspectAPedia.com

How to recognize asbestos on or in heating or cooling ducts Transite or sonno duct asbestos recognition Risks associated with asbestos in duct work Warning about amateur asbestos removal on HVAC systems

Asbestos Materials on or in the Air Conditioning or Heating System Duct Work

This chapter describes the inspection of heating and air conditioning ducts for visual evidence of asbestos materials in or on HVAC ducts. The photograph shows asbestos paper heating duct wrap. Asbestos in these locations is a possible hazard which may require special attention. We also warn about signs of amateur asbestos removal which may merit additional testing and cleanup work. This is part of a document which describes the inspection of residential air conditioning systems (A/C systems) to inform home buyers, owners, and home inspectors of common cooling system defects.

Here is a photo of a coated (note the silver color) asbestos-fabric air handler vibration damper. Also see VIBRATION DAMPERS for more discussion of this possible asbestos source, and for visual recognition of a wide range of asbestos or asbestos-containing products in buildings, see Asbestos: visual identification of asbestos-suspect materials in buildings - a photo guide.

If readers return to the first chapter or view the A/C chapter index, the major components of an air conditioning system are described, sketches and photographs are provided, and common defects for each component are listed along with visual or other clues that may suggest a problem or probable failure of A/C components. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution. © Copyright 2008 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use the links at page left to navigate this document or to go to Other Website Topics. Green links at left show where you are in our document & website.

Asbestos - Ductwork Safety Recommendation

Another example of asbestos duct wrap is shown in this photograph. During an inspection of the heating or air conditioning duct system and air handler, look for what may be asbestos containing insulating material on the heating system. Cement asbestos "millboard" used as a partial heat shield on wall/ceiling surfaces. White corrugated insulating material on and hanging from pipes, white paste material surrounding certain plumbing joints. White "paper" wrapped on outside of some heating ducts. White woven material used as flexible joint between some heating ducts. White woven material used as flexible joint in the vibration damper between air handler the duct work.

TRANSITE and SONNO-DUCT Air Conditioning or Heating Duct Material Warnings

While the transite pipe shown here was in use as an exhaust flue (what is the fire rating and fire clearance required?), this material was also used in some buildings for in-slab duct work. Caution: Down flow furnace in building with concrete slab and with perimeter duct work raises questions: what is the duct work made of ?

Transite pipe, if used, may be a an asbestos hazard.

Sonno Duct (spun composition material) may have absorbed water, collapsed, and be blocking the duct line and potentially inviting a termite infestation or a mold contamination problem in the building.

More identification photographs of transite pipe in buildings can be found at Asbestos Transite Chimneys & Flues and at
Transite Pipe HVAC Ducts

ASBESTOS RISKS - on Heating and Cooling Ducts

While there may be no conclusive data nor studies which evaluate hazards regarding presence of this material in residential buildings, it is generally considered by the scientific community to be a potential health risk. It is also a potential economic risk as future buyers may be concerned about this material. Disposal costs for this material are increasing. Depending on condition and location of asbestos material, treatment ranges from doing nothing to complete removal. Removal could involve significant costs. You should obtain proper technical information and health and safety guidelines before attempting to do anything with this material. It is the breathing of fibers when this material is disturbed, not it's mere presence, which is considered a health risk. When the material is not found in living areas in poor condition treatment is not usually an emergency and you have ample time to become informed, obtain estimates, and select a course of action.

... HEAT.036 - Asbestos - Lab Test Requested
... HEAT.031 - Asbestos - material unconfirmed; choice of treatment affects. costs If the material is confirmed as asbestos, depending on its condition and location, treatment ranges from doing nothing to complete removal. Removal would involve significant costs and is generally the preferred course.
... As we discussed during the inspection, a
... A number of treatment options are available. Choice of treatment can make a big difference in possible costs of handling the material. You should obtain proper technical information and health and safety guidelines before attempting to do anything with this material.

... HEAT.032 - ASBESTOS MATERIALS on HEATING SYSTEM - Details See Asbestos Materials on Heating System at the end of your report for some important details.

Asbestos Warning: incomplete removal, amateur workmanship on the Air Conditioning or Heating System

Improper/Incomplete Asbestos Duct Insulation or Pipe Wrap Removal: Caution: When we observe that a considerable amount of this insulating material has been removed leaving scraps or remainders and without cleaning and sealing of the exposed ducts or piping, we issue the following warning: Asbestos duct or piping insulation removal has not followed approved methods and procedures: we saw that HVAC duct work or piping has not been cleaned nor sealed, and that the suspect material has been left in some places - details not found when materials were removed by trained professionals. Unprofessional removal of controversial materials in a building may raise health, legal, or marketing concerns for future property owners. You should attempt to obtain documentation regarding who did what to the property regarding this topic. Additional testing to assure that no hazards or legal issues remain, may involve significant expense. expense; possible, hazardous materials.

AIR CONDITIONING SYSTEMS Chapter Index

To continue reading this air conditioning inspection guide, use links to the document chapters at left or below. Links shown in green font indicate where you are in this document.

Technical Reviewers

More Information on Building HVAC Systems and Duct SystemsDiagnostic Inspections and Repairs

For more information about fiberglass as an indoor air quality concern see:

• Fiberglass in Indoor Air, HVAC Ducts, and Building Insulation
• Fiberglass Particle Identification in the Fiberglass Test Laboratory
• Goodman Gray Flex Duct Deterioration and Failures
• Mold in Fiberglass Insulation
• Optimum Indoor Air Filters
• Owens Corning Flex Duct Deterioration and Failures
• World Trade Center Dust Particle Identification

For more information about asbestos as an indoor air quality concern with focus on easy ways to identify asbestos materials in buildings, see:

• Asbestos Identification in Buildings: How to find & identify asbestos-containing materials
• Asbestos in Good Condition
• Asbestos HVAC Ducts - Asbestos Materials On or In Heating and Cooling Duct Work
• Asbestos paper duct wrap
• Asbestos Transite Chimneys, Flues, & Pipes in Buildings
• Asbestos under the microscope
• Asbestos Vibration Dampers & Asbestos in the Air Handler
• Ceiling tiles: How to recognize ceiling tiles that may contain asbestos
• Examples of unusual uses of asbestos in buildings

• Asbestos: How to find and recognize asbestos in Buildings - visual inspection methods, list of common asbestos-containing materials
• Asbestos HVAC Ducts and Flues field identification photos and guide
• Dust from the World Trade Center collapse following the 9/11/01 attack: the lower floors of this building contained spray-on fire-proofing asbestos materials.
• Asbestos Information Links: Asbestos Detection, Testing, Recognition, Hazards, Field Photos, and Information Sources, including health-related links such as legal services and information about mesothelioma and other cancers.

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