The Ultimate Guide to Eliminating Odours in Air Ducts

Aug 7, 2018 | Ductwork Cleaning

An air duct is something that helps us work well on cold or hot days by ventilating the building and controlling the temperature , but sometimes these ducts may actually be spreading odours.

These odours are an indication that there may be dust or debris accumulated in the system, or it could be something else.

We suggest you first identify the type of odours since different odours will have different solutions.

1. Musty or moldy Smell

Musty smells can originate from AC vents since AC dehumidifies the air and the water in it may not drain properly. The moisture left behind creates a perfect condition for mildew and mould to flourish.

Dirty filters also promote mould growth and it can be fixed by replacing the filter of the AC. If this doesn’t solve the problem, the next step is to call a professional to clean the conditioner.

Cause: Mouldy vents

Level of seriousness: Low, but it is associated with an increased risk of respiratory infections.

2. Rancid Smell

When animals like rodents die somewhere inside your air ducts, the decomposing carcass gives off a rancid smell. This problem is particularly tricky to solve since it can be difficult to locate the carcass inside the ductwork.

The best solution is to try and find the dead animal, and remove it carefully wearing gloves and masks, and sanitize the area. In most cases you should call a professional, since accessing ductwork systems and cleaning them requires a certain level of expertise.

Cause: Dead animals

Level of seriousness: Low

3. Rotten Eggs

A strong smell of rotten eggs indicates a gas leak. This is a sign for you to turn off your gas and call emergency services immediately. Do not use any electrical devices or turn the lights on as it may lead to an explosion.

Cause: Gas leak

Level of seriousness: Hazardous, must be dealt with immediately

4. Cigarette Smoke

The fumes from a cigarette permeates the coil of air conditioners, so when you turn it on, your office might have the old smoke circulating along with the air.

To remove the smell, you can either clean the coil, or replace it.

Cause: Smoke absorbed in the coils

Level of seriousness: Low

5. Sewage

The smell of sewage indicates a ruptured sewer vent pipe in your ductwork. Methane, a dangerous gas, is usually the source of this smell which is being released from the ruptured pipes.

When this happens, the best step is to call a professional as soon as possible, due to the hazards associated with it.

Cause: Ruptured pipe

Level of seriousness: Hazardous, must be dealt with immediately

6. Urine

The strong smell of urine coming from your heating or cooling system is an indication of vermin infestation in your ductwork systems. Mice and other small animals defecate in the air vents, and the stench is circulated.

Using poison to deal with the vermin infestation is a bad idea, since the animals will die in the ductwork itself, causing even fouler odour to circulate the building.It is best to lay out multiple traps on the entrance to the vents and other areas of entry into the system. Again it is best to call a professional to handle this since it may require access to certain areas of your ductwork and / or proper pest control.

Cause: Vermin infestation in your ducts

Level of seriousness: Low

How to avoid odours in my duct system?

Prevention is better than cure but many businesses are unaware of the necessities of getting your ductwork cleaned, while others are unaware of how often they should be cleaned, and often face consequences.

The best solution to eliminating odours in ductwork systems is to get it checked and cleaned regularly by a professional service.

With the right equipment and knowledge, debris, dust, mould, and microorganisms in ductworks can be easily dealt with

Need a professional service to eradicate odours in your air vents?

innovatefm provides high quality Ductwork Cleaning services, complete with certificates of cleanliness. Our trained teams of cleaners can clean ductwork systems as per Building Engineering Services Association (BESA) TR19 standards.

Give us a call on (0161) 724 8999 (option 2) or email us at​ for more information.