Below you can find a list of all the common phrases and abbreviations used within the industry.f you have any further questions, or do not see a term that you think would be relevant, please contact us to let us know and we will update our records accordingly.



Access Panel  Fitted to kitchen ductwork systems and canopy/extract plenum to enable unrestricted access for regular cleaning and inspection of the internal surfaces and in-line components.

ACS  Air Conveyance System.

AHU  Air Handling Unit

Air Filtration  This reduces the concentration of solid particles in the airstream to a level that can be tolerated by the process or space occupancy purpose.

Air Hygiene  The provision of fresh, hygienic air to working environments is critical to avoid the ill health of occupants, especially in areas such as kitchens and laboratories.  Mechanical ventilation and extraction systems require regular maintenance, cleaning and testing in order to effectively provide clean fresh air.

BSEN  British Standard-European (Regulation)

BS EN15780  The European Standard for Ventilation Maintenance, clearly defines vital goals to be achieved by anyone responsible for the ventilation in any building, by recognising that different room uses require different standards and that newly installed ductwork should be handed over in a clean condition.

Coil Cleaning  This is a specialised area of care within ventilation systems.  The coil is in the air flow path on all ventilation systems, therefore it has a direct effect on the rate of air flow, efficiency of heat transfer and indoor air quality.  Any blockages decrease the amount of air passing through the system which leads to increased pressure drop.  This in turn increases fan horsepower requirements which increase current consumption resulting in higher energy costs.

COSHH  Control of Substances Hazardous to Health

COSHH Testing  Sometimes known as LEV (Local Exhaust Ventilation) testing.  This test is required by the Health & Safety Executive to ensure the equipment performs as originally intended and continues to adequately control the exposure of employees to substances hazardous to health.

Deposit Thickness Test  This is a method for determining the dirtiness or cleanliness of a system.

Duct Cleaning  The mechanical cleaning or physical removal of debris and other foreign matter from the Air Conveyance System.

Ductwork Inspection  Using the latest technology and procedures and employing extensively trained and experienced personnel for the inspection and cleaning of HVAC/Duct systems, to ensure continuous and efficient operation.

EPBD  Energy Performance of Building Directive

EVHA  European Ventilation Hygiene Association. Their objectives are to promote the Ventilation Hygiene industry within Europe and lobby for legislation, being recognised as the sign of competence and quality.

Fire Dampner  A device that prevents the migration of fire where air ducts penetrate fire barriers such as floors, walls and partitions.

Grease Extraction  The accumulation of grease-laden deposits in unclean extract ventilation systems.

Great Extraction  Where grease-laden air is drawn directly from relevant areas and is vented out into the atmosphere.  Canopies capture the smoke and filters are in place to trap grease particles as air passes through the system.

Grille Cleaning  Ventilation grilles protect a building’s heating and cooling system to keep large objects from entering the ductwork.  They all require periodic cleaning as they collect dust and other airborne debris. 

Hood/Canopy Cleaning  The process of removing grease that has accumulated inside the ducts, hoods, fans and vents of exhaust systems of commercial kitchens.

HTM 0301  Health Technical Memorandum 03-01 - Key issues include:

  • The Verification testing of Critical Ventilation Systems, including pre 2007/8 theatres
  • The Validation testing of New Build conventional and ultra-clean ventilation (UCV) systems
  • The prevention and control of healthcare related infections
  • Layout of minimum requirements for the design of air handling units (AHU) with regard to safe access for routine inspection and maintenance and the control of Legionella
  • Controlling exposure to harmful organisms, toxic and anaesthetic substances

HTM 2025  Health Technical Memorandum 2025 Ventilation in Healthcare Premises

HVAC  Heating, Ventilation and Air Conditioning

HVCA  Heating and Ventilation Contractors' Association

IAQ  Indoor Air Quality. A term which refers to the air quality within and around buildings and structures, especially relating to the health and comfort of building occupants. 

Kitchen Extract Cleaning  The majority of catering establishments feature a canopy extraction system within the kitchen to control the build up of heat, steam and grease emissions in the cooking area.  The filters in the canopy act as a good “first line of defence” against grease deposition but still allow the smaller particles to pass into the extract ductwork system.  These accumulate over time and pose hygiene and fire risks.  Canopies can be regularly cleaned by staff the ductwork is usually above a ceiling and can pass through numerous walls and floors before reaching the discharge point.  These hidden sections require specialist attention for cleaning to the TR19 standard.  This standard also indicates a recommended frequency of cleaning dependent on the number of hours per day the kitchen is operational.

LEV  Local Exhaust Ventilation. A form of engineering control that encloses the material, equipment or process as much as possible and ensures that air flow is into the enclosure at necessary rates.

Theatre Validation  The control of hospital airborne infections through the verification and validation of the air ventilation systems in critical areas such as hospital theatre suites and sterile service departments. This ensures compliance with HTM03-01 and HTM2025 regulations.

TR/17  One of two publications that the then HVCA amalgamated in 2005 along with the DW/TM2 to produce the TR/19 standards.

TR/19  Best Practice Standard from B&ES is used by specifiers, consultants and building legislators to ensure that ventilations systems are properly maintained.  Adherence to the standards in TR/19 will provide detailed, recognised proof that the ventilation system in a building is safe and well maintained, which is vital for securing insurance policies.

Vacuum Test  A vacuum pump “pulls” air, moisture and contaminants out of the system after it has been repaired and before it is recharged.  The deeper and more complete the vacuum, the more contaminants trapped within the system, its components and even in the compressor oil are removed.  Prior to pulling a vacuum and charging a system you should recover, repair and check for leaks.

Ventilation Hygiene  Ventilation systems (including air conditioning systems) should be regularly and properly cleaned, tested and maintained to ensure that they are kept clean and free from anything which may contaminate the air.

Ventilation Survey  Inspection of local exhaust ventilation systems (LEV), air conditioning systems (EPBD) and ventilation ductwork systems to national standards.

WEL  Workplace Exposure Limit. Regulates limiting workers to excessive exposure of toxic chemicals while on a project.

Wet Film Thickness Test  This is a safety check to assess the condition of kitchen grease extract systems.