Ductwork Cleaning for HVAC, Air Conditioning & Kitchen Extract Ventilation

Ductwork cleaning

Specialist air and ventilation hygiene solutions.

WTS is a leading UK air hygiene and environmental engineering services company offering expert ventilation ductwork cleaning, disinfection and maintenance services for all commercial heating, ventilation and air conditioning (HVAC); air duct distribution and kitchen extract systems.

All our duct cleaning contracts are carried out by experienced air hygiene specialists, strictly in accordance with the latest industry standards including BESA TR19 dealing with the internal cleanliness of ventilation systems, and BS EN 15780 to ensure all required regulatory and insurance standards are met.

With improvements to indoor air quality, reduced levels of airborne contamination, better working environments, fewer health and safety risks, and opportunities to increase operating efficiencies, it’s clear that there are significant benefits to be gained from maintaining the cleanliness of your ventilation ducts and air handling systems.

Ventilation duct cleaning solutions

Our specialist ventilation duct cleaning, disinfection and air hygiene solutions offer a number of important benefits including:

  • Improved Indoor Air Quality

    Improve indoor air quality to promote workplace health and well-being, employee comfort, and attendance and productivity issues.

  • Cleaner, Healthier Workplace Environments

    Remove allergens, dust, debris, bacteria, moulds and fungi from ductwork, vents, filters and air handling units for a cleaner, healthier indoor environment.

  • Manage Fire Risks more Effectively

    Kitchen grease extract systems cleaned in accordance with latest fire safety regulations and insurers requirements.

  • Reduce Foul Odours

    Remove debris, grease, oils, slimes and microbiological contaminants that can cause persistent and foul odours.

  • Improved Air Flow Efficiency

    Restore air flow efficiency by removing dirt, debris, grease and other contaminants from ducts that can build-up restrict air flow velocities.

  • Long Term Energy Savings

    Clean ductwork and air handling systems to restore operating efficiencies for long term cost and energy savings.

  • Compliant with Latest Regulations & Guidelines

    All works carried out by experienced air hygiene specialists in accordance with current BESA, BSRIA, DoH and Health & Safety regulations and good practice guidelines.

Full national UK coverage

With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of trained technicians and air hygiene specialists, we can offer professional ventilation ductwork cleaning and disinfection solutions to businesses throughout the UK and Ireland.

Contact WTS today to learn how our HVAC, air conditioning and kitchen extract ventilation solutions can help you. To speak with one of our experts call us on 0330 223 31 31 or simply use this button.

Is there a legal requirement for air duct cleaning?

HVAC installations, air conditioning and kitchen extract ventilation systems are now commonplace in many business premises and business owners, directors, property and facilities managers have a legal obligation to maintain them properly to minimise airborne contamination and reduce health and safety risks. Having a regular programme of air duct cleaning and maintenance won’t just fulfil your legal obligations, it will also ensure that your HVAC and ventilation systems are working at optimum efficiency.

Why ventilation ductwork cleaning is important

In the UK the Workplace (Health, Safety and Welfare) Regulations 1992 fall under the wider Health and Safety at Work etc Act 1974 (HASAWA) and provide a detailed list of requirements for employers. One of these requirements relates specifically to the ventilation of workspaces. The rules state that business owners, directors and managers need to provide fresh air to their workers, either naturally or by means of mechanical ventilation.

In factories, offices or other indoor environments where the ventilation is provided by a system of mechanical air handling units, fans and air ducts rather than just by opening a window, employers are legally required to maintain, inspect and clean their ventilation systems to ensure they are hygeinic and safe to use. Companies must also keep detailed records to show they are complying with the law.

What about commercial kitchens?

Commercial kitchens are commonly found in many factories, hospitals, hotels, schools, restaurants and other catering operations. Mechanical fume and grease extract ventilation is used to remove cooking smells and airborne grease, carbon and water vapour from the kitchen, often operating at high temperatures. If regular ductwork cleaning is not carried out, grease and dirt can build up inside the ventilation systems to cause problems such as reduced airflow, foul odours and increased fire risk.

In addition to the general requirements for regular cleanliness, employers and managers of commercial kitchens are also required to consider fire safety issues and must include the ventilation extract systems in their fire risk assessments. This is a specific requirement of the Regulatory Reform (Fire Safety) Order 2005.

Additionally, the person responsible for the premises must then put in place and maintain suitable precautions to manage and reduce the potential fire risks involved (the fire management plan). If a fire associated with poorly maintained ventilation ducts, filters, screens and fans does occur and it can be proved that you haven’t been cleaning or maintaining the systems as often as required you may find yourself in trouble with the UK safety regulators… there may also be a chance that insurers may refuse to pay out on any claims if you’ve failed to comply with their requirements.

Sick building syndrome and ventilation issues

Sick Building Syndrome (SBS) is the name given to a wide range of health issues which can affect workers in indoor environments such as offices. Employees often start to complain of fatigue, irritation or headaches as a consequence of poorly-ventilated buildings and airborne contaminants.

If you’re not maintaining your air conditioning systems or ventilation ducts to the correct standards, this can lead to reduced workplace health and well-being, employee comfort, and attendance and productivity issues. Having employees off sick can lead to increased costs to the business and decreases in efficiency. In severe cases, or in businesses where lots of people are complaining of the same symptoms, business owners may even face investigation and potential prosecution for not taking adequate precautions to protect the safety and health of their employees.

Can bacteria, mould and fungi grow in ventilation ducts?

One of the other serious issues which can be caused by damp, dirty, poorly maintained ventilation ducts is the concealed growth of bacteria, moulds and fungi. Ductwork, by its very nature provides the ideal breeding ground for microbiological contaminants, many of which can cause serious health issues for building occupants. As air flows through the ducts it passes over such contaminants and unwittingly acts as a distribution network, spreading airborne pathogens into and around building workspaces.

Hospitals and healthcare environments

In healthcare environments such as hospitals and care homes where building occupants are often ill, elderly or immuno-compromised the distribution of airborne infectious diseases via dirty and contaminated ventilation systems can have very serious consequences and must be avoided.

Failing to maintain ventilation ducts which leads to illness, disease or even fire can result in disruptive investigations by the health and safety regulator, and potentially significant fines for companies who are proved to be negligent.

How often should you get your air ducts cleaned?

The manufacturers of ventilation equipment will often provide detailed guidance on cleaning methods and frequencies in their operating and maintenance manuals (O&M manuals) and it is recommended that this advice is followed. However, where guidance is not available cleaning schedules can be developed by our air hygiene experts based on a number of site-specific factors which can include:

  • When was the air handling and distribution equipment installed and when it was last cleaned/maintained?
  • What is the size/volume of the workspace, kitchen or cooking area serviced?
  • How frequently is the workspace used?
  • Are there any access restrictions?
  • Are there scheduled periods of down-time/shut down when cleaning works can be completed?
  • What filtration techniques are used?
  • Consideration for local fire and building regulations.
  • What does the fire risk assessment and fire management plan say?
  • What about budgets for the work.

Dealing with new HVAC ductwork installations

New or replacement installations should be designed and installed to allow easy access, cleaning and maintenance of components.

During the installation process all ductwork components and equipment should be kept undamaged, clean and free of any construction related debris and other contaminants.

Once the installation is complete a thorough pre-commission inspection should be carried out to ensure the ductwork system is clean and free from misplaced construction equipment, dirt, debris, oils, and other contamination prior to handover and full commissioning of the HVAC installation.

Air conditioning ductwork

When to clean existing air ducts

It is important that existing ductwork installations be kept free from dust, dirt, bacteria, mould, fungi and other contaminants that can affect the cleanliness, safety and performance of the system. We recommend that air duct cleaning or replacement should be carried out if any of the following are identified:

  • Significant water damage.
  • Dust, debris or other particles exhaust from the system in to the workspace.
  • Blockages to airflow.
  • Foul odours from the system.
  • Bacterial, mould, fungal growth is evident.
  • Build-up of grease and oils.

How oftet should commercial kitchen ducts be cleaned?

It is important that kitchen extract systems are regularly inspected and cleaned to control fire risks caused by the build-up of grease, oils, fats and other contaminants.

TR19, the guide to good practice titled Internal Cleanliness of Ventilation Systems, published by the UK’s Building Engineering Services Association (BESA) gives clear guidance on the requirements for extract cleaning based on cooking methods, estimated volumes of airborne grease, and daily usage of the kitchen facilities.

Intervals for Kitchen Extract Cleaning from TR19

Perceived level of grease productionTypical ExampleUp to 6 hrs daily use6-12 hrs daily use12-16 hrs daily use16+ hrs daily use
LowNo significant production of grease laden aerosols during normal daily food production operations12 months12 months6 months6 months
MediumModerate production of grease laden aerosols during normal daily food production operations12 months6 months4 months3 months
HighHeavy significant or continual production of grease laden aerosols during normal daily food production operations6 months3 months3 months2 months

It should be noted that property insurance policies may call for higher cleaning frequencies for grease extract ductwork systems than those identified in TR19. Failure to comply these specific requirements set by the insurers may invalidate any property insurance policies that are in place.

How do you clean air ducts?

In small mechanical ventilation systems used in private homes or small businesses, manual ductwork cleaning might be the best way of maintaining your ducts. Few businesses or private individuals will have access to the equipment needed to carry out the cleaning themselves however, and most prefer to get air hygiene experts such as WTS in to make sure the job is done professionally.

Most modern buildings have had their ventilation systems installed with on-going maintenance in mind. This means that the duct elements are installed in sections, with access panels at each end.

If other methods of cleaning are impractical, a technician may need to get inside the ventilation ducting and scrub, wash and clean the dirt, dust and grease away. This is often the best way of cleaning ducts which are heavily fouled with grease, as the deposits adhere to the internal surfaces of the ducting and are often very difficult to remove.

It’s important to remember that anyone undertaking this type of work must be properly trained for work in confined spaces, with another technician on standby outside the duct should they run into difficulties. Once cleaned, the interior of the ducting is often treated with a special coating to prevent further grease sticking as readily in the future.

Other methods of cleaning ductwork

In most cases, pulling on the protective PPE clothing and getting inside the ventilation ducts won’t be necessary. The experienced ventilation duct cleaning specialists at WTS can look at the specifics of your operation, and recommend the best and most cost-efficient cleaning solutions for your needs.

The two most commonly used methods for cleaning industrial ventilation ducting in the UK are the “air hose” and “rotary brush” techniques. Both of these techniques depend on having ventilation ducts in sealed sections with suitable access panels as mentioned above. If you have ventilation ducting in some other configuration, our specialists will be able to advise on the best solution.

Air hose and vacuum cleaning techniques

One of the most popular ways of cleaning smaller ventilation ducting systems is using a technique which employs an air hose fitted with a diffuser.  The air hose and diffuser are inserted into one end of the section of duct being cleaned, and compressed air is then forced through the hose. The noise of the hose thrashing around inside the ducting can become noisy.

The compressed air dislodges any dirt, dust or debris which has built up inside, and this is then drawn into a high-powered vacuum cleaner at the other end of the section.

It’s an effective method on small sections of ventilation ducting, but can be noisy. On larger sections, the hose may move around too much. This could mean that the cleaning isn’t as effective as it might be, and that it might take longer overall as sections have to be cleaned several times.

Rotary brush and vacuum cleaning methods

This duct cleaning method is perhaps the easiest to understand and is very similar to the way traditional chimney cleaning works.

Initially the ducts being cleaned are put under negative pressure to prevent dust and dirt escaping in to the workspace. A high-powered vacuum cleaner is then used at one end of the section being cleaned, but instead of an air hose, a rotary brush is used. The brush is twisted inside the section of ducting to dislodge any dust, dirt or debris, this is then sucked out using the vacuum.

The dust and dirt is fully contained within the vacuum, and although there is some noise, it is less noisy and disruptive than using the air hose method. After treatment, a special air hygiene biocide may be used to deter bacteria and other microorganisms from growing again.

Once the cleaning works are complete the workspace is typically subjected to a minimum ten air changes before people are allowed to re-enter the building.

Simple housekeeping measures to optimise HVAC performance

Going-forward the build-up of dirt, debris, bacteria, moulds, fungi etc. in HVAC equipment and air duct systems can be minimised by ensuring some simple housekeeping measures are followed including:

  • Keep all filters in good, clean condition.
  • Carry out regular preventive maintenance of HVAC equipment and ductwork cleaning.
  • Site any air-inlets to ensure only clean air is used.
  • Ensure internal environments served by the ventilation systems are kept clean and well maintained.
  • Ensure all HVAC and duct components are kept clean, dust free and dry.

Useful standards for air duct cleaning and specification of ventilation systems

  • BESA TR19: Guide to Good Practice

    TR19: Guide to Good Practice – Internal Cleanliness of Ventilation Systems, published by the UK’s Building Engineering Services Association (BESA) was published in 2013 and offers practical guidance on testing and cleaning of air distribution and kitchen extract ventilation systems to meet required standards. It incorporates reference to UK and European Standards for cleanliness of air duct systems. It also highlights best practice for ensuring that kitchen extract ductwork is maintained to minimise the risk of fire associated with grease accumulation a subject not covered by EN15780.

  • BESA DW 172: Specification for Kitchen Ventilation Systems

    DW/172: Specification for Kitchen Ventilation Systems, published by BESA was published in 2018 and reflects current legislation and the latest cooking techniques and design of catering equipment, by all sections of the catering industry.

  • BS EN 15780:2011

    Ventilation for buildings. Ductwork. Cleanliness of ventilation systems. BS EN 15780:2011 details the assessment criteria for cleanliness and ductwork cleaning procedures for air conditioning and ventilation systems.

  • HTM 03-01

    HTM 03-01 – Heating and ventilation of health sector buildings, is published by the Department of Health and relates to premises in the health sector. It provides guidance on the design and management of heating and specialised ventilation systems in health sector buildings.

Specialist ductwork cleaning and air hygiene solutions

With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of trained technicians and air hygiene specialists, we can offer professional ventilation ductwork cleaning and disinfection solutions to businesses throughout the UK and Ireland.

Contact us today for more information or for your FREE, no obligation quote.

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Further reading…

More information about our indoor air quality services … here →

Ductwork Cleaning for HVAC, Air Conditioning & Kitchen Extract
User Rating
5 based on 647 votes
Service Type
Ductwork Cleaning for HVAC, Air Conditioning & Kitchen Extract
Provider Name
Water Treatment Services,
14 Commercial Street,Manchester,United Kingdom-M15 4PX,
Telephone No.0330 223 31 31
United Kingdom & Ireland
Expert ventilation ductwork cleaning and disinfection services for all commercial heating, ventilation and air conditioning (HVAC); air distribution and kitchen extract systems.