Kitchen Extract Duct Cleaning: Why It Matters in Commercial Kitchens

The areas of a commercial kitchen extraction system you can see are only part of the picture.

During cooking, grease-laden vapours are drawn through the canopy and into the extract system. Some grease is captured by filters, but some can travel further into the ductwork before cooling and accumulating on internal surfaces.

Over time, this build-up can become a significant hygiene and fire risk - creating a consistent maintenance challenge and cost. 

Regular kitchen extract duct cleaning helps remove these deposits and forms an important part of maintaining a safe and effective commercial kitchen extraction system.

Why does grease build up inside kitchen extract ductwork?

Commercial kitchen extraction systems operate in a particularly challenging environment.

Cooking can produce a combination of:

• Grease and oil vapours

• Smoke

• Steam

• Heat

• Airborne particulates

The extraction system is designed to remove these contaminants from the kitchen, but that also means they travel through the system. Grease that isn't captured at the canopy can settle further along the ductwork.

The rate of accumulation will vary depending on factors such as the type of cooking, operating hours, extraction system and effectiveness of existing grease filtration and management.

Why is kitchen extract duct cleaning important?

One of the biggest concerns is fire risk. Grease deposits within an extraction system are combustible. As they accumulate, the amount of combustible material present within the ductwork increases.

But fire risk isn't the only consideration. Heavy grease accumulation can also contribute to odours, hygiene issues and restricted airflow through the extraction system.

Effective kitchen extract duct cleaning therefore forms part of maintaining the safety, cleanliness and performance of the wider system.

What does commercial kitchen extract cleaning involve?

Commercial kitchen extract cleaning needs to consider more than the parts of the system that are immediately visible.

The extraction route can include the canopy, filters, ductwork and fan, with sections of ductwork often running through ceilings, risers or other parts of the building.

For cleaning to be effective, contractors need appropriate access to the areas requiring inspection and cleaning.

This is why access panels and the overall design of the extraction system can make such a difference to long-term maintenance.

How often does the kitchen exhaust duct need to be cleaned?

Cleaning frequency depends on the kitchen and how the extraction system is used.

A busy commercial kitchen operating for long hours and producing significant quantities of grease may require more frequent cleaning than a kitchen with lighter use.

BESA's TR19® Grease guidance provides recommended cleaning frequencies according to usage, but the actual cleaning regime should also reflect the condition of the system and rate of grease accumulation.

Regular inspection is therefore important for understanding what's happening inside the ductwork rather than relying solely on a fixed calendar.

Can you reduce grease build-up inside kitchen extract ductwork?

Cleaning removes grease that has accumulated, but there are also technologies designed to manage grease within the system between cleans.

Quintex’s Ecofix automatically introduces a biological mist into the kitchen extraction system.

The droplets adhere to grease, oils and fats on internal duct surfaces. Selected Class 1 bacteria then consume the grease and volatile fatty acids, converting them into water, CO₂ and a minimal biomass residue.

This provides continuous grease management throughout the extraction system rather than waiting for grease to accumulate before addressing it.

Will I still need to have the kitchen extract duct inspected?

Yes, the inspections are always required at the intervals set out in TR19, but with Ecofix working continuously, the frequency of kitchen extract duct cleaning is greatly reduced. If a clean does become required over time, the process of cleaning is made quicker and easier.

Taking a proactive approach to kitchen extract grease

Commercial kitchen extract cleaning is essential for removing accumulated deposits, but operators don't necessarily have to wait for grease to build up before doing something about it.

A wider grease-management strategy can consider:

• Grease filtration

• Ductwork condition

• Cleaning frequency

• Access for inspection and maintenance

• Fire-risk management

• Ongoing grease accumulation between cleans

TR19 provides a framework for assessing and managing grease accumulation, but even a compliant extract system will contain some combustible grease deposits between inspections and cleaning. Reducing grease accumulation further can therefore provide an additional layer of protection by reducing the available combustible material within the ductwork and, consequently, the residual fire risk.

For kitchens with high grease loads or difficult-to-access ductwork, continuous grease management can provide another layer of protection.

Quintex Ecofix is designed to continuously manage grease within commercial kitchen extraction systems, helping reduce accumulation, control odours and reduce fire load.

Find out more about Ecofix commercial kitchen grease management, or contact Quintex to discuss the requirements of your kitchen extraction system.

Kitchen Extract Duct Cleaning FAQs

Commercial kitchen extract ductwork needs to be designed, installed and maintained with factors such as fire safety, grease accumulation, cleaning access and ventilation performance in mind. Requirements can involve Building Regulations and recognised industry guidance including BESA DW/172 and TR19® Grease.

For a wider explanation of the requirements, read our Commercial Kitchen Ventilation Requirements: UK Regulations Explained guide.