You can feel the bad odor coming from the air vents of your house or office. In some cases, the smell is persistent. In other cases, it comes and goes and its intensity changes over time. Even though the symptoms may vary, they are a sign of a serious problem which must be identified and dealt with quickly. Find out more about the main causes of a foul smell coming from the air ducts and how to resolve them.
Mold and Mildew
If there is a musty smell in the rooms and it does not go away no matter how often you open the windows or use an air spray, then you are most certainly dealing with mold or mildew inside the air vents. Both of these are types of fungus. They can have a variety of colors from white, pink, yellow and green to black. They can be damaging to surfaces and pose serious health hazards. Two conditions must be present for mold and mildew to grow. These are moisture and warmth. When the surface is moist and the temperature is above 65 F, the fungus will begin to grow and spread.
Mold and mildew usually appear in the air vents of buildings in warm and humid climates. However, they can also grow due to structural issues. When there is no proper insulation, for instance, the colder air easily gets into contact with the warmer surface and condensation appears. When moisture is present, the fungus is quick to follow.
In order for the issue to be resolved, the air vents must be properly cleaned. Special chemicals, which are deadly for mold and mildew, but safe for people and animals, have to be used. The cause of moisture must be eliminated as well.
If there is a dead animal inside the air vents, the smell can be quite unpleasant and get more intense when the weather gets warmer. Most often, the animals found inside the ductwork are rodents, but it is also possible for the problem to come from birds and insects. The bad smell is not the only issue. Dangerous pathogens may be spread around the house.
In such cases, the source of the smell must be identified and removed. The air vents must be properly cleaned and disinfected. You must also take measures to prevent the access of animals into the ductwork.
Less often, the bad odor can come from gasses which have been released into the air ducts. If the heat exchanger of the HVAC system has a leakage, it will release combustion gasses such as carbon monoxide into the air ducts. These gasses can pose a serious health threat. Action for resolving the problem must be taken immediately.
If the structural components and finishes of a building release chemicals in gas form, they can be carried by the HVAC system and their bad smell can come from the air vents. In this case, the dangerous materials must be removed and all surfaces including the walls of the air ducts must be properly cleaned.
When there is a bad odor coming from the air vents, you must take the necessary steps to deal with the problem without delay.