Hazards of Mold in Your Ductwork

Mold contamination within air duct systems can pose detrimental health effects to building occupants if left uncorrected.  If mold exists within your air ducts make a plan to investigate the source of the problem, isolate the problem area, and remove the contaminants.

Understanding Mold

Molds are part of the natural environment. Molds are fungi that can be found anywhere – inside or outside – throughout the year. About 1,000 species of mold can be found in the United States, with more than 100,000 known species worldwide.

When excessive moisture or water accumulates indoors, mold growth often will occur, particularly if the moisture problem remains uncorrected. While it is impossible to eliminate all molds and mold spores, controlling moisture can control indoor mold growth.  Molds are usually not a problem unless mold spores land on a damp spot and begin growing. They digest whatever they land on in order to survive. There are molds that grow on wood, paper, carpet, foods and insulation, while other molds feed on the everyday dust and dirt.

Since mold requires water to grow, it is important to investigate the source of the moisture to prevent mold growth.

Hazards of Mold in Your Ductwork

Ventilation systems are designed to distribute a recirculate air within a home.  If mold growth is within the ventilation system, or near an air intake, mold spores can be spread throughout a home.

“Toxic mold syndrome” remains controversial and unproven, but experts agree that it’s best to limit exposure to molds.  The most likely adverse reaction to mold is a respiratory allergic reaction in mold-sensitive people. These reactions are similar to other respiratory allergies, causing sneezing, watery eyes, nasal discharge and congestion.

Cleaning Air Ducts

Consider having the air ducts in your home cleaned if there visible mold growth inside hard surface (e.g., sheet metal) ducts or on other components of your heating and cooling system.

There are several important points to understand concerning mold detection in heating and cooling systems:

  • Many sections of your heating and cooling system may not be accessible for a visible inspection, so ask the service provider to show you any mold they say exists.
  • You should be aware that although a substance may look 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.
  • If you have insulated air ducts and the insulation gets wet or moldy it cannot be effectively cleaned and should be removed and replaced.
  • If the conditions causing the mold growth in the first place are not corrected, mold growth will recur.

How to Remove Pet Urine Odor from Air Ducts

Pet urine within the air ducts is an extremely unpleasant odor.   Sometimes trouble shooting where the pet urine odor is coming from can be quite difficult.  Here are some great instructions on how to remove pet urine odor from air ducts.

Locating the Sources

Before you can correct a pet urine problem you have to identify all of the areas affected.  Sometimes it can be difficult to isolate or identify source of the pet urine odor.  One of the easiest methods of locating where pets have urinated is through the use of a UV black light.  First darken the room, and then shine the UV black light near vent register openings, pet urine stains will glow in the dark.

Cleaning the Surrounding Areas

As pets urinate into the vent registers, the urine is likely to collect around the carpet or hardwood floor near the air vent register opening.  If you do not clean the areas around the air vent register opening the scent of the urine will cause the pet to instinctively re-soil the area.

One of the best methods for removing the odor is to use baking soda and white vinegar.  Prior to using baking soda and white vinegar, be sure to check with your flooring manufacturer to see if it will affect your floors finish.  Never use ammonia or ammonia based cleaning products.  While ammonia is a good cleaning product, one of the components of pet urine is ammonia, and the odor of the ammonia can lead your pet to instinctively re-soil the area.

DO NOT spray cleaning chemicals into the air ducts, only specific chemicals may be used within air ducts.  Your ventilation system is designed to redistribute air and can potentially distribute the volatile cleaning fumes throughout the home.  If you have accidently poured chemicals within the air ducts, open the doors and windows and call a duct cleaning professional.

Duct Cleaning

After you have cleaned the surrounding area of the air vent registers, hire a professional air duct cleaning contractor.  Debris within the air ducts will harbor pet urine odor.  As the heating and air conditioner is in operation, pet urine odor can distribute throughout the entire home.  An duct cleaning contractor will be able to access the HVAC system and help you to restore the HVAC system to its proper condition.

Ductworks Featured In NADCA DucTales

NADCA Member Ductworks Appears on Cable TV Show

Many Companies within the HVAC Inspection, Maintenance and Restoration Industry have seen a dirty HVAC system, but what about on filled with 5,000 pounds of sand and black powder?  Recently Ductworks Inc. of Arvada, Colo., a long-time NADCA member, participated in the Do-It-Yourself  cable network program “Disaster House.”

The show damages a house to then show viewers how to prevent the damages, how to clean them up, and then what to know before filing an insurance claim. In the particular episode, a six foot sand-foot tall, 5,000 pound sand castle was blown up to simulate an extreme case of dirty air ducts and Ductworks was called in to clean the mess up.  They got the system back up to pristine conditions after a full day of hard work.  Although most homes do not see 5000 pounds of dust and debris, it goes to show that even the dirtiest residential air ducts can be cleaned.

SOURCE: NADCA DucTales January / February 2010