Industrial and Local Exhaust Ventilation LEV


 General ventilation title 1

 Industrial ventilation - LEV

  What is Local Exhaust Ventilation (LEV)?



An LEV is an engineering control system to reduce exposures to airborne contaminants such as:


                       Dust                                                      Fumes

  Gases                           Mist                                   Vapour



Generally a system will have some or all of the following components:

 Capture Hood or Plenum , Ducting , Air Cleaner , Filter/ Abatement Plant, Air Mover (Usually Fan) and Discharge Point,  Monitoring of the Air Flow  

 Filtration Abatement Plant and Emissions may be required, together with an Air Supply System


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All parts of the LEV system must be effective and correctly designed ensuring compliance to COSHH, CE Directives, PUWER, DSEAR and environmental regulations. Please see the relevant pages in this web site for specific details of all the applicable components, parts and legislation.



How can legislation and environmental considerations affect your company? 

With the introduction of COSHH, the Environmental Protection Act (EPA) and Integrated Pollution Prevention and Control regulations, more consideration is being given to the rigorous control of workplace air quality and emission levels for a wide range of chemicals.

Emissions and air quality limits, for substances that are hazardous to health are getting more stringent with lower applicable limits.

COSHH regulations stipulates that no work that exposes anyone to substances hazardous to health, shall be carried out until an assessment has been made and appropriate control measures are implemented.

Hierarchy of Control


Hierarchy of control


This is the Hierarchy of Control that we adhere to at R&B Industrial. In our project engineering department, we specifically focus on Engineering Controls on this pyramid.

“To be effective long-term, Engineered Control Measures must be practical, workable and sustainable”

COSHH 2002.

For this reason it is crucial that the plant, processes, substances, pollutants, methods and systems of work, maintenance, local environmental regulations and any other relevant information is fully investigated and understood.

HSG258 - Controlling airborne contaminants at work


So how can we help you with your requirements?

We have over 35 years of experience in designing; installing, commissioning and maintaining dust and fume extraction systems. We are a unique company in the field, as we not only supply and manuafacture in-house, we also provide consultancy services when appropriate. Furthermore, we have an installation team who specialise in fitting and commisioning systems to standard.  

Our speciality is determining the best solutions for our customers. Whether that is in the office or on-site, we aim to improve our customers working lives, by reducing the risk of their day-to-day activities, whilst being as environmentally aware and energy efficient as possible in an ever changing engineering world.


How can we do this?

We study material safety data sheets and your specific requirements, always applying good workplace control principles and advising customers accordingly.

In some instances other control measures may be more appropriate.

Such as:

  • Substance substitution
  • Design changes in the process
  • Enclosing processes
  • Simple modifications
  • Changes to existing hood design.

All of these considerations can often improve LEV performance considerably.

For general ventilation systems, further optimisation can be made using room occupancy sensors to automatically switch ventilation on / off as required; ventilation is controlled by Variable Air Volume (VAV) and Constant Volume Dampers (CVD); see general industrial Ventilation air handling units and associated systems.doc


We can carry out comprehensive pre-design DSEAR/ATEX assessments. This ensures that:

  • Hazardous Areas are correctly zoned: 22, 21, 20 dusts. 2, 1, 0 vapours, mists, gases
  • Air flows are correctly specified for assurance of correct zoning
  • Correct equipment category is specified
  • Correct control measures are put in place such as air flow monitoring and alarms.


Following this the correct LEV hood design is crucial to ensure air flows and flammable dust / solvent etc capture is effective. This enables us to potentially reduce extents of zones saving our customers potentially many thousands of pounds.



We carry out project and ventilation works in the following areas: Hampshire, Berkshire, Avonmouth, Dorset, Devon, Wiltshire, Somerset, Oxfordshire, Buckinghamshire, Middlesex, Northamptonshire, Surrey, Sussex, Wales, Bedfordshire, Gwent, Cambridgeshire, Cardiff, Carmarthenshire, Ceredigion, Clackmannanshire, Derbyshire, Essex, Gloucestershire, Greater London, Gwynedd, Hertfordshire, Isle of Wight, Nottinghamshire, Kent, Leicestershire.