Tag: Internal Fiberglass Insulation

Dangers of Air Duct Cleaning Chemicals

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Air duct cleaning service providers may tell you that they need to apply a chemical biocide to the inside of your ducts to kill bacteria (germs), and fungi (mold) and prevent future biological growth.   Careful consideration should be taken before allowing the application of chemicals within your air ducts.  Due to the varying ranges of temperature, humidity and air turbulence there are very few chemicals that are approved for the use within ventilation systems.

Chemical Off Gassing

Organic chemicals are widely used as ingredients in cleaning and sanitizing products.  Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids.   Even a nearly odorless material can cause significant problems when re-circulated through air ducts in a closed environment.  VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects.

NADCA’s Position Regarding the Use of Antimicrobials

The National Air Duct Cleaners Association’s new position regarding the use of antimicrobial chemicals is as follows: “At this point in time, until EPA clarifies their position, NADCA does not recommend the use of any sanitizer or disinfectant products in air ducts.” This position was adopted to generate awareness among NADCA members of the potential legal liabilities they face by selling and applying antimicrobial chemicals. This is strictly a matter of managing legal risks. NADCA’s position deals specifically with sanitizers and disinfectants, not with any other product claims. Also, this position covers only air ducts, not HVAC components such as coils

No EPA Registered Products for Fiberglass Air Ducts

There are no products that are currently registered by EPA as biocides for use on fiberglass duct board or fiberglass lined ducts so it is important to determine if sections of your system contain these materials before permitting the application of any biocide.

If  You Choose to Use Chemicals in your Air Duct Cleaning Project

  • Review the product sheet showing usage and application of the product.
  • Review the Material Safety Data Sheet (MSDS) to understand if chemicals will cause any health or property concerns.
  • Review the Fact sheet on the product classification being applied.

If You Have a Problem Related to Chemicals Applied Within Your Air Ducts

  • Open doors and windows to ventilate the area with fresh air.
  • Operate the fan of the HVAC system
  • Exit the premises if negatively affected.
  • Contact and Industrial Hygienist to discuss the problem.  Be sure to have a copy of the MSDS.

Fiberglass Air Duct Liners | A Serious Indoor Air Quality Concern

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Most commercial air duct systems are internally lined with fiberglass duct liners.  Deteriorating fiberglass duct liner is a very common cause for indoor air quality complaints and adverse health effects.

Fiberglass Duct Liner

Fiberglass internal duct liner is commonly used in many commercial heating, ventilation, and air conditioning (HVAC) system.  Fiberglass duct liner provides sound attenuation by dampening noise from HVAC equipment, and sound from adjacent office spaces.  Fiberglass duct liner provides thermal insulation for air ducts, preventing the air ducts from losing expensive conditioned air.

Fiberglass Duct Liner Deterioration

Over time internal fiberglass duct liner is exposed to varying degrees of air turbulence, temperature and humidity.  These environmental changes take its toll on the duct liner, breaking down its primary seal.

The primary seal is a black gritty coating on the surface of the duct liner which locks down the fiberglass fibers.  Deteriorated primary coating migrates through the ventilation system depositing within HVAC components and eventually entering the indoor air.

After the primary seal has fully deteriorated, it allows raw fiberglass fibers to be exposed to the airstream.  Turbulent airstreams wick the raw fiberglass fibers through the ventilation system, creating additional deposits within HVAC components and exposing building occupants to raw fiberglass fibers.

Health Effects of Fiber Glass Fibers

Health effects from exposure to fiberglass can be different depending on the fiber size and type of exposure.  Fiberglass, at a minimum, is an acute physical irritant to the skin, eyes, and upper respiratory tract.

  • While no long-term health effects should occur from touching fiberglass. Rashes can appear when the fibers become embedded in the outer layer of the skin.
  • Eyes may become red and irritated after exposure to fiberglass as occupants touch horizontal surfaces with deposits of fiberglass fibers, and rub their eyes.
  • Soreness in the nose and throat can result when fibers are inhaled. Asthma and bronchitis can be aggravated by exposure to fiberglass.
  • Temporary stomach irritation may occur if fibers are swallowed.

How Can Fiberglass Air Ducts Be Repaired?

If caught in the early stages of deterioration the internal fiberglass duct liner can be repaired.  Fiberglass duct liner can be resurfaced with an encapsulate specifically designed for HVAC systems.   Initially a commercial air duct cleaning needs to be performed to remove the foreign debris from the air duct surface to ensure for a proper bond.  After the air duct system is cleaned, the encapsulate is applied to the air duct surface locking down the fiberglass fibers.

If the internal fiberglass lining to too deteriorated, the lining must be removed and replaced.  If the damage is localized,  new internal internal insulation can be installed within the ducting.  If the damage is extensive, consider removing the damaged insulation and wrapping the air ducts with an external fiberglass insulation.