Are access doors needed for ductwork to be cleaned?

Ventilation ductwork within a building performs an extremely important role and are integral to the safety and wellbeing of everyone who works there.

Without clean ductwork, building occupants could find they start to become unwell, potentially seriously so in places such as a hospital, and there’s a greater risk of kitchen fires too.

Therefore, as an employer or building owner, it’s vital to comply with health and safety regulations and get your supply and extract ductwork cleaned regularly.

But what exactly is needed for ductwork to be cleaned and are access doors really necessary? We examine the ins and outs of ductwork cleaning.

Why are clean ducts important?

Health and safety requirements specify that ducts must be kept clean and all cleaning undertaken by a suitably qualified individual. This means that this person will work for a B&ESA (Building and Engineering Services Association) accredited company working to TR19 standards.

Bacteria and mould can very quickly build up in ducts, especially those which provide humid or warm conditions; this is caused by dust and debris building up and the subsequent movement of air over accumulations as shown in the photograph below.

Be aware, bacteria and mould happily grow in uncleaned ducts where birds have been sheltering.

If ducts are allowed to build up to and then remain in this state, harmful allergens and pathogens will circulate around the building, causing allergies and illness to workers. In some cases these pathogens have been proven to be fatal, with Legionnaire’s Disease and the spread of MRSA caused.

For this reason, it’s essential that ducts are kept scrupulously clean and proper maintenance and testing is carried out.

The importance of access doors

The Health and Safety Commission’s Code of Practice stipulates that all ducts must be cleaned thoroughly and that all contaminants are removed from the duct via the cleaning and maintenance carried out.

To do this the cleaners will require access to the duct but without access doors installed this could be rather tricky. Ducts run in the ceilings and through the walls and potentially have a lot of twists, turns and corners. These are the places which are the most difficult to clean without an access door and rather ironically, these are also the places where dust and debris is most likely to collect! And where dust and debris are, bacteria and mould follow shortly after so it’s imperative to make sure the whole inner surface of the duct is properly cleaned out.

What kind of access doors are required?

All access doors should be made from the same material as the rest of the duct and of the same thickness too. This is to provide adequate protection against the spread of fires. They should be manufactured and fitted in accordance with the B&ESA (Building and Engineering Services Association) DW144 standard.

Positioning of the access door should be in accordance with Table 3 from the B&ESA (Building and Engineering Services Association) TR19 Standard as shown below.

Control Dampers Both sides
Fire Dampers Both sides
Heating/Cooling Coils Both sides
Attenuators (Rectangular) Both sides
Attenuators (Circular) Both sides
Filter Sections Both sides
Air turning Vanes Both sides
Changes of Direction One side
In Duct Fans/Devices Both sides
Inlet/Exhaust Louvre One Side

You could be forgiven for thinking that this table will result in a lot of doors being fitted. Its fair to say that any accomplished ductwork cleaner being told by his customer that access doors have
been fitted to Table 3 TR19 will happy in the knowledge that more than enough doors are fitted. It is possible, by consultation with an accredited ductwork cleaning company, that the number of doors fitted to a system can be reduced.

Generally speaking the two types of access doors fitted to duct are as shown above.


The cleaning of ductwork isn’t a matter which can be skipped over without resulting in potentially serious consequences for the occupants of the building. Cleaning operatives can only do their job properly if they have the necessary access to the inner part of the duct and this is why access doors are imperative to making sure the duct remains clean and clear of debris.

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