LEV System Design Consultancy
Comprehensive Local Exhaust Ventilation (LEV) design consultancy services – tailored from initial concept through to fully specified, compliant system designs. Whether you require a centralised system or a single extraction point, our bespoke solutions are supported by detailed 2D and 3D modelling to enable accurate project planning and competitive tendering.
LEV Systems Designed for Compliance and Employee Safety
- We’ve been designing LEV systems in line with COSHH regulations and HSG258 guidance since 2002, with employee protection and regulatory compliance at the core of every solution.
- LEV is an essential preventative measure regulated by COSHH 2002
- Systems fully compliant with HSE, COSHH 2002, HSG258, DSEAR
- Designed with your operators, processes, and safety needs in mind, providing a clean, safe working environment for your employees.
- Independent and brand-neutral – we select the right equipment for your application, not the other way around
- Bespoke, end-to-end design support. We offer a comprehensive 5-step design service to create a solution that meets your needs and aligns with HSG258 standard.
A well-designed LEV system is a shared responsibility between the system owner, supplier, and service provider. At McCarthy Environmental, our role is to make that collaboration seamless – providing expert guidance at every stage to deliver a fully compliant, effective solution.
Our BOHS-qualified project engineers take the time to understand your processes, materials, and workspace. This insight allows us to design LEV systems that are not only tailored to your environment but also aligned with HSE regulations, ensuring long-term protection for your workforce.
By prioritising safety, compliance, and usability, our solutions help improve productivity, reduce downtime, and support staff wellbeing and retention.
LEV Design Regulations
Local Exhaust Ventilation (LEV) is regulated by the Health and Safety Executive (HSE) through a selection of key publications, primarily:
- HSE’s HSG258 guidance
- COSHH Regulations 2002 (as amended)
- DSEAR Regulations 2002
These regulations provide guidance to ensure LEV systems remain compliant with EH40/2005 Workplace Exposure Limits (WELs) to protect employees from exposure to harmful levels of airborne contaminants.
Our engineers are qualified by BOHS and are trained to interpret and apply these regulations throughout every stage of the design and implementation process – ensuring your system delivers the required level of control and keeps your workforce safe.
“LEV suppliers provide goods (an LEV system) and may then act as a service provider. Designers are responsible for interpreting the requirements of the employer and advising on an effective LEV system which is capable of delivering the required control”
— HSG258 (2011) 2.18
Finding the Right LEV Solution for your Extraction Needs
At McCarthy Environmental, our dedicated Projects & Design department is made up of a competent and experienced team capable of delivering bespoke design solutions for a wide variety of applications – ranging from complex centralised systems to individual extraction points.
Our BOHS qualified staff have over 60 years of combined experience working with large-value projects, high-profile customers in various sectors including Formula 1, Education, Aerospace, Automotive, and Composites. We work closely with you to develop a value-added partnership – ensuring the system we design is the right fit for your application, your workspace, and your workforce.
Step 1: Site Survey
Our BOHS qualified designers visit your site to understand your extraction requirements, your production materials and processes, and the available layout of your production space.
Step 2: Benchmarking
We consult the relevant HSE regulations and guidelines to determine what type of LEV capture hood is the most suitable for your processes and materials. This determines the exposure benchmark.
Step 3: Technical Drawings
We create 2D and 3D drawings to scale, mapping out the most efficient route for the LEV ducting and equipment within your building, taking into account operational workflow and physical constraints.
Step 4: Extraction Calculations
We calculate the exact air volume required to run the LEV system efficiently, choosing a suitable air mover solution from our range of quality suppliers. As an independent company, we’re not tied to any specific brands – so we always recommend the solution that best fits your application, performance needs, and budget.
Step 5: Proposed Solution
Once the extraction hoods, ductwork and air movers have been determined, we can provide a quote for your ideal LEV solution that will ensure your extraction is HSE compliant and keep your workforce safe from airborne contaminants.
Why Choose McCarthy Environmental
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Frequently Asked Questions
We understand that designing and implementing an LEV system can raise a number of questions – especially when it comes to compliance, technical requirements, and choosing the right solution for your workspace. Here, we’ve answered some of the most common queries our clients have, to help guide you through the process with confidence.
What regulations are there for LEV?
Several key publications guide the design and implementation of compliant LEV systems, including:
- HSE’s HSG258 Guidance – Controlling airborne contaminants at work
- COSHH Regulations 2002 (as amended) – Control of Substances Hazardous to Health
- EH40/2005 – Workplace Exposure Limits
- EH44 – Dust in the Workplace
- DSEAR 2002 – Dangerous Substances and Explosive Atmospheres Regulations
These documents help us ensure that your LEV system provides the right level of control to protect against harmful airborne substances in line with UK legal requirements.
What calculations determine the most suitable extraction solution?
From HSG258, we can determine the recommended face velocities and capture velocities (the speed of air at the point where the substance is being extracted). This tells us, depending on the size of the hood, what volume of air needs to be pulled through.
Duct velocities are also recommended in HSG258. The contaminant will determine what speed is needed. For example, heavy dusts need to be pulled through ductwork at a high speed to avoid deposits dropping out (collecting within the ductwork). On the other hand, fumes and gases have a lower recommended duct velocity, and therefore will not require such a powerful air mover.
Any additional bends or extensions to the ductwork will affect the required air velocity, which will be considered in your proposed solution.
Additional calculations include air density, to adjust for air temperature, and maximum vapour concentration of a liquid.
What qualifications are required for an LEV supplier?
At a minimum, all of our design engineers hold a BOHS P602 in Basic Design Principles of LEV.
With decades of combined experience, our team is fully equipped to provide systems that meet your legal obligations and operational needs.