How to ensure Duct Cleaning work was carried out properly?

Any commercial property has a legal obligation to ensure its ductwork is cleaned and maintained regularly. Ventilation and air conditioning systems should be subject to a regular maintenance schedule to ensure that air quality meets legal standards, workforces are protected, and insurance companies are satisfied. Duct cleaning should be carried out by a fully qualified and accredited team. In doing so, employers can ensure they’re meeting legal standards. However, after having your ductwork professionally cleaned, how can you verify the work carried out?

Visual Inspection

The most simple way to check any duct cleaning work would be to have a visual inspection of the equipment. To do this properly, you should look at any ductwork systems before work is carried out so you can see a visual difference after completion. Ductwork can build up dust and debris, which is obvious to the naked eye. Following duct cleaning work, equipment should be noticeably cleaner. However, while a visual inspection is quick and easy to carry out, you may miss aspects that are more hidden and difficult to spot.

Before & After Evidence

At Deduct, we provide HD videos of your ventilation system on request with every job. Similar to carrying out a visual inspection, a before and after video will show the result of cleaning work. Photographic evidence and schematics are detailed in your post-clean report. However, a video of specific locations or items of equipment can be much more informative.


Clean hospital ductwork

Hygiene Certificate

Following the completion of any duct cleaning work, we will provide an insurance-compliant certificate for your records. This certificate is proof of the work that has been carried out and is suitable for satisfying any insurer’s requirements.

Micron Readings Report

Microns are a unit of measurement. The level and frequency of duct cleaning should be based on these figures. BESA released new technical requirements for TR19 in relation to legal requirements for duct cleaning. Providers must supply a post-clean report (PCR) that includes recommendations based on micron readings. The report itself must detail micron readings for each test location, which can give you an idea of any air quality issues. Where readings exceed certain thresholds, you can see where duct cleaning is needed more regularly.

In accordance with BESA’s TB/009 technical bulletin, the post-clean report (PCR) should also include:

  • An executive summary highlighting key risks
  • A clear indication of whether the system was cleaned in its entirety, and if not, the reason why and a possible solution
  • Any other hazards identified during the cleaning process
  • The current cleaning frequency and a recommendation for a new cleaning frequency based on the micron readings
  • A sufficient number of before and after cleaning photographs to represent the system condition, including at least seven from the TR/19 test locations (section 7.41)
  • A schematic diagram of the system layout, showing the areas that were cleaned and any areas that could not be cleaned, with test locations identified


There are many ways to ensure that duct cleaning work has been carried out properly. Owners and employers need reassurance that their ductwork has been cleaned to a high standard to ensure the safety of their workforce, meet legal obligations and satisfy insurers. At Deduct, we’re happy to carry out a free, no-obligation site survey and risk assessment. If you’re concerned about your ductwork, give our team a call today at 0333 772 0089.

By incorporating the specific requirements of the TB/009 technical bulletin into the post-clean report, you can verify that the duct cleaning work has been carried out comprehensively and in compliance with industry standards and regulations.