A guide to the different types of Local Exhaust Ventilation (LEV)

Want to provide effective protection for your workers while also not breaking any safety rules?

That’s why it’s essential to understand the different types of local exhaust ventilation systems available and identify which is best – and most suitable – for your business.

Designed to control dust, vapours, fumes, and mist, LEV systems are on the frontline when it comes to protecting employee health in industrial and manufacturing workplaces.

Read now: ‘What is a Local Exhaust Ventilation system?

What are the different types of Local Exhaust Ventilation?

The most common types of LEV systems include:

  • Enclosing hoods
  • Capture hoods
  • Receiving hoods
  • Down-draught benches
  • On-tool extraction systems
  • Portable extraction units

While each of these different local exhaust ventilation types work to remove contaminants, the way in which they control them is distinct.

Enclosing Hood Systems

As the name suggests, enclosing hoods partially (or fully) surrounds the hardware generating airborne contaminants.

Because they physically contain dust or fumes before they’re able to escape, enclosing hood systems are among the most effective types of local exhaust ventilation.

Examples include:

  • Spray booths
  • Cabinet enclosures
  • Tipping hoppers/stations
  • Sealed processing units
  • Galvanizing Baths

Enclosed systems are used where maximum containment is required, particularly where hazardous substances may present a high risk of exposure.

Capture Hood Systems

Rather than enclosing the process entirely, capture hoods are closely positioned to the source of the contamination to capture airborne particles as they are generated.

Typical applications include:

  • Welding extraction
  • Grinding operations
  • Cutting and sanding processes

To ensure effective capture, the hood needs to be positioned carefully, and airflow taken into consideration.

Proper system design, maintenance, and testing are critical.

Receiving Hood Systems

Receiving hoods are positioned to take advantage of the natural movement of contaminants such as hot fumes or vapours, as the air will be more likely to flow upwards.

These types of LEV are commonly found above:

  • Furnaces
  • Ovens
  • Heat treatment processes
  • High-temperature manufacturing equipment

Receiving hoods are particularly effective where thermal currents aid the movement of contaminants.

Because they partially rely on natural airflow patterns, it’s crucial that receiving hoods are carefully positioned.

Down-Draught Bench Systems

These types of LEV are commonly used in smaller-scale manual operations, and work by pulling contaminated air down through a perforated work surface into the extraction system.

They’re ideal for processes where contaminants are generated directly in front of the operator.

Typical uses include:

  • Sanding
  • Polishing
  • Small-part grinding
  • Laboratory work

Down-draught benches maintain a clean work surface while keeping contaminants away from where the worker is breathing.

On-Tool Extraction Systems

On-tool extraction systems integrate the extraction process directly into the handheld tools or machinery being used.

These are useful local exhaust ventilation types where flexibility and mobility are essential.

Examples include:

  • Dust extraction on saws and grinders
  • Portable woodworking tools
  • Construction equipment

Contaminants are captured immediately at source, and are increasingly important in industries with strict dust exposure regulations.

Portable Extraction Units

In some workplaces, fixed extraction equipment is impractical.

For that reason, portable extraction systems can be moved between workstations or processes as required.

They’re commonly used for:

  • Temporary welding work
  • Maintenance operations
  • Small workshops
  • Low-volume extraction tasks

Portable types of local exhaust ventilation depend on the correct setup, airflow management, and regular testing to maintain effectiveness.

Choosing the Right LEV System

Selecting the right types of local exhaust ventilation will depend on various factors, including:

  • The type of contaminant being generated
  • The quantity of airborne material produced
  • The layout of the workspace
  • The frequency and duration of exposure
  • The specific process being carried out

No single LEV solution will suit every environment, which is why professional assessment and system design are critical.

The Importance of LEV Testing and Maintenance

Every LEV system, whatever the type, requires regular testing and maintenance to ensure it continues to perform effectively.

Without regular assessment, even the best designed systems can fail to provide the level of protection required.

Professional testing helps ensure systems are:

  • Capturing contaminants effectively
  • Operating within required airflow ranges
  • Compliant with COSHH regulations

At Pennaire, our industry-leading expertise is backed by a reputation for quality, precision, and compliance.  

Our service engineers possess a BOHS P601 certificate, guaranteeing that your LEV systems are inspected to the highest possible standards.

Want to book a service? Or need expert advice? Our experienced team is here to help.

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