Can Mould Grow In HVAC Ducts?

Unfortunately yes, mould is capable of infecting the ductwork of an HVAC system in your home.

While air conditioners are known as natural dehumidifiers, the process they use to create chilled air produces water and condensation. Additionally, furnaces produce heat, which is something mould needs to grow. 

The primary source of mould growth in HVAC ductwork is due to available food sources, which would be dust in this case. Unclean ductwork will have clumps of dust and other organic pollutants scattered within it due to old filters. 

Likewise, dust is made from dead skin cells and human oils, a food source for mould. Once an air duct or fan is infected, mould spores can be distributed whenever the furnace or air conditioner is activated. 

Signs of Mould in Ductwork

The spread of mould spores not only makes its growth more available, but it also can cause symptoms such as; 

  • Strong musty odours

  • Itchy eyes

  • Coughing and Wheezing

  • Congested nose

  • Trouble breathing

Mould is accompanied by strong, awful smells when it has fully matured fruiting bodies. By the time a strong scent is emitted by your HVAC system, it is clear that the mould has progressed to an advanced stage. At that point, only a professional can help remove the problem. 

What Kinds of Mould Grow in HVAC Ducts

Mould does not discriminate when it comes to infecting spaces; it’ll take what it can get. That being said, mould will grow anywhere that provides ample conditions. Bedrooms with a temperature range of 40-70 degrees, over 60% moisture range, and food source will have mould growth. 

Common species of indoor mould are

  • Acremonium

  • Alternaria

  • Aspergillus

  • Fusarium

  • Mucor

  • Stachybotrys Chataram (black mould)

  • Trichoderma

  • Ulocladium

All of these mould species can produce an array of health risks due to the mycotoxin content in their spores. 

How to Remove Mould from Infected Ductwork

Removing mould from infected HVAC ductwork will require professional assistance due to how inaccessible ventilation systems are and how prolific mould is. If the mould is not removed correctly, it can easily re-populate itself throughout the house. 

Additionally, this failure will not remove mould irritation symptoms, which can become severe illnesses if left untreated. 

The only way to remove mould from ductwork is to have professional mould remediation performed. Mould remediators will inspect, locate, remove, and restore the infected area as nothing happened. 

The unique part of remediation is that there is little chance of the mould source coming back, as it has been ultimately killed and removed with proper equipment. 


Comments are closed here.