AC System Disinfection

December 07 2015
ac disinfection

After your AC system has been cleaned, it is usually disinfected. Now this is a generic term and can range from at worst companies not doing it or spraying water, to disinfecting with bleach or ammonia! So what is disinfection? Why is it done? And how do you know if it is undertaken properly? 

To start with, what is disinfection?

Disinfection is a process whereby a sanitizing/ disinfecting chemical is converted through an ultra low volume machine into a dense mist and is fogged into an AC Duct The mist touches all areas of the duct. The purpose is to kill any bacteria or mold that may be within the duct.

Why is it done?

Disinfection is done to ensure the ducting is not just cleaned, but sanitized/ disinfected. The process of disinfection should only be undertaken once the dust/ dirt has been removed from the ducting. There is never any use applying any fumigant to a dirty duct. This is because the fumigant will just sit on top of the duct and create a sludge within the duct which is hard to clean, it will also not disinfect anything. There are many chemicals that are used for fumigation, but there is one main rule to take note of – has the fumigant been registered with the EPA and is it safe to use in the AC system? Always stay away from companies that claim that their product is EPA approved as the EPA does not approve any chemical for use.

See the registered list below:

How do you know if disinfection is done properly?

The first and most important step is to only use a NADCA certified company when cleaning or fumigating your ducting. The second part is ask questions. It is easy to see from companies responses if they know what they are talking about. Here is a guide to some questions to ask:

  • What is the active ingredient within the disinfectant?
    Stay away from products that contain chlorine, ammonia, bleach or any product that has solvents. Products which have hydrogen peroxide (which we use), Tetraacetylethylenediamine, Ethaneperoxoic acid. Always ask to see the chemical MSDS.
  • Does the product keep disinfecting once is has been applied?

If yes, do not use it. This is exactly why we use hydrogen peroxide – we love that it leaves no residue. Everybody has different sensitivities to chemicals and we would rather be safe and ensure that we do not contaminate the air with a chemical that keeps working after we leave.

  • How will you protect our furniture?
  • When will it be safe to enter the property again?

If you have any questions about disinfection or AC Cleaning, please contact us on 04 361 7949 or email us at