These types of fan are easy to identify due to the three many parts making it up. The firs being the fan itself with its blades, along with a separate motor and the final component being the drive belt that turns the fan itself.
They can also vary significantly in size and uses. Which also means when looking to add them to an asset list double checking they aren’t part of an extract system or something else is extremely important to avoid assets being added to a list twice.
An LEV system is not a simple extract system but is mainly used for the removal of harmful fumes and dust. This video below prepared by the Health and Safety Executive explains in more detail. As I often find people confusing normal ventilation systems with Local Exhaust Ventilation, LEV for short when they are very different pieces of equipment with different maintenance and legislation.
Lots of different jobs across different industries involve work processes that create dust and
fumes. If these are not controlled properly people can breathe them in and develop diseases
such as asthma, lung scarring and cancer.
Every year thousands of people in Great Britain die as a result of breathing in harmful dusts
and fumes at work. The common way businesses can control dust and fumes is by using local
exhaust ventilation systems or LEV, also called extraction or fume control.
LEV systems can be very effective at controlling dust and fumes but it is vital that people
understand how LEV works so that they buy the right LEV and use it properly.
LEV systems all work in the same way.
In this example 2 hoods are used to enclose the saw blade, one above the table and one
below. The LEV airflow into these hoods carries the wood dust away. The contaminated extracted
air is transported through the duct work to the filter and fan unit. The filter removes
the dust from the air. The fan creates the airflow. It’s the motor that moves air through
An LEV system will often provide extraction at more than one machine. Getting the right
type of LEV hood is the most critical step. If the hood design is right for the process
then it is possible to control the dust and fume. Soldering work produces fume which can
Here the worker is protected by the LEV hood and system but how does it work. The hot fume
cloud rises but is prevented from reaching the woman’s breathing zone by the enclosing
hood. The LEV airflow draws the fume filled air away. The enclosure and the airflow act
together to protect the worker’s health. Enclosures can be very effective but in practice
LEV hoods come in all shapes and sizes, from ones which are large enough to stand in to
others that are tiny and built into tools.
LEV hood design is critical to controlling dust and fumes. For almost any dusty or fumy
process there is an LEV hood and system design that will provide effective control.
Make sure your LEV is the right sort and is properly applied. Well designed and applied
LEV systems can really protect your workers’ health.
Professional advice is widely available.
You can get competent help from your trade association or a professional adviser.
Printed guidance on how to choose and use LEV is available from the HSE and a range
of information and links can be found at the HSE LEV website.