Introduction

In today's industrial and manufacturing environments, air quality and safety remain pivotal to safeguarding worker health and meeting compliance requirements. A well-functioning Local Exhaust Ventilation (LEV) system is essential in controlling harmful airborne contaminants, from dust to hazardous fumes, that can pose significant health risks over time. However, merely installing an LEV system is not enough. To ensure optimal efficiency and adherence to safety regulations, it's imperative that your LEV system installation is done to the highest standards.

This article explores what makes a quality LEV installation, how to evaluate your current setup, and the critical role of regular inspections, maintenance, and component considerations, such as a bag filter. By the end, you'll be equipped with the knowledge to ensure your LEV system meets regulatory standards and effectively protects those who rely on it.

Why Proper LEV System Installation is Essential

Local Exhaust Ventilation systems are designed to capture and remove airborne contaminants at their source before they spread into the broader environment. These systems are particularly common in industries like welding, woodworking, pharmaceuticals, and chemical manufacturing, where particulates or vapors are often present. The benefits of a well-installed LEV system are manifold:

  1. Worker Health: Exposure to airborne toxins can lead to serious respiratory conditions, allergies, and other health issues.
  2. Regulatory Compliance: Failing to meet the required safety standards can result in fines and legal actions, impacting both the business's finances and reputation.
  3. Operational Efficiency: A well-functioning LEV system prevents equipment from becoming clogged with dust or particulates, which can hinder performance and lead to costly repairs.


LEV system installation is not a task to take lightly. Incorrect installation not only reduces the system's effectiveness but may also result in a system that fails to meet regulatory standards, exposing workers to avoidable risks.

Key Indicators of a Quality LEV System Installation

How can you tell if your LEV system installation is up to standard? Here are some signs to look for in a quality installation:

1. Precise Hood Positioning- The hood is the component of an LEV system closest to the contamination source. An effective hood should be positioned as close as possible to the emission source to capture contaminants efficiently. If the hood is too far or poorly aligned, the system will struggle to contain particles, leading to inadequate containment.

2. Appropriate Ductwork Design- The ductwork is responsible for transporting contaminants from the hood to the filter or exhaust. Poorly designed ductwork can lead to a buildup of dust and fumes, decreasing the system's efficiency. Signs of substandard ductwork design include excessive bends, leaks, or blockages, which reduce airflow and increase pressure drop within the system. Each bend in the ducting should be minimized to maintain a smooth flow and reduce the risk of clogs.

3. Optimized Airflow Rates- Airflow rates in LEV systems must be calibrated to specific workplace conditions. An airflow rate that is too high can lead to turbulence and excessive energy use, while a rate that is too low may result in inadequate contaminant capture. Professionals who install and maintain LEV systems measure airflow to ensure it meets the demands of the particular workspace, taking into account the type of contaminants present and the volume of air required to transport them.

4. Quality Filters- Filters are crucial to the effectiveness of an LEV system, trapping harmful particles before clean air is released back into the environment. The bag filter is a common choice for many LEV systems, known for its durability and high particle-holding capacity. A poorly installed or low-quality filter can compromise the entire LEV system, so it's essential to ensure that any filters in use are well-fitted, maintained, and replaced as needed to uphold air quality standards.

5. System Testing and Commissioning- After installation, your LEV system should undergo rigorous testing and commissioning. This process assesses the system's performance, including its ability to capture contaminants and maintain suitable airflow rates. Testing should be carried out by certified professionals who use specialized equipment to measure capture velocity, duct velocity, and filter efficiency. Proper commissioning ensures the system operates as intended from day one and provides a reliable benchmark for future inspections.

Compliance Standards: How to Assess Your LEV Installation

To evaluate whether your LEV system is up to standard, you should be familiar with the various regulations governing LEV installations and maintenance. In the UK, the Control of Substances Hazardous to Health (COSHH) regulations mandate that LEV systems must be tested at least every 14 months to ensure they are performing correctly. Here's how to make sure your LEV installation is compliant:

  1. Periodic Testing and Examination: Regular LEV testing is mandatory for legal compliance. By conducting scheduled LEV servicing, any issues can be detected early, ensuring the system remains in optimal working condition. During these tests, airflow rates, hood placement, filter integrity, and overall containment efficiency are assessed.
  2. Documentation and Record-Keeping: Keeping detailed records of each test, inspection, and maintenance activity is essential. These records serve as proof of compliance during audits and help identify recurring issues that might suggest areas for improvement in the system.
  3. Expert Assessments: It's recommended to have a professional assess your LEV installation periodically. Qualified engineers can provide an objective evaluation and offer recommendations for improvement, if necessary, ensuring your LEV installation not only meets regulatory standards but operates at peak efficiency.

Signs Your LEV System May Need an Upgrade

An LEV system is not a “fit and forget” solution. Over time, even the best installations can degrade, particularly if maintenance is neglected. Here are some signs your LEV system may need an upgrade or re-evaluation:

  1. Decreased Performance: If you notice an increase in airborne dust or contaminants, this could be a sign that your LEV system is no longer capturing particulates as effectively.
  2. Increasing Repairs: Frequent repairs may indicate that parts of the system, such as ductwork or the bag filter, are deteriorating. Continuous breakdowns are a clear sign that the system may need an overhaul.
  3. New Hazardous Substances: If your workplace introduces new processes or materials, such as chemicals that weren't part of the original LEV design considerations, your system may need to be reconfigured to handle these new contaminants effectively.



Regular LEV servicing can address these issues, ensuring that any necessary updates are made before the system's performance suffers.

The Role of Maintenance in Sustaining LEV Standards

Maintenance is the backbone of a compliant LEV system. A neglected system will inevitably fail, leading to the accumulation of hazardous substances in the air and potential regulatory breaches. Regular maintenance can prevent these issues, but it must be done by professionals who understand LEV systems in depth.

Key maintenance activities include:

  1. Filter Replacement: Filters must be inspected regularly, particularly in environments with high levels of particulate matter. The bag filter, for instance, is a reliable option but still requires periodic replacement or cleaning to maintain efficiency.
  2. Duct Cleaning: Over time, particles can accumulate in the ductwork, impeding airflow and reducing system efficiency. Regular cleaning can prevent this buildup and improve overall air quality.
  3. System Calibration: Airflow rates should be checked regularly and recalibrated as needed. Ensuring that airflow remains at optimal levels is crucial for effective contaminant capture.

Maintenance schedules vary based on the industry and type of LEV system in use. Consulting a professional service provider for LEV servicing can ensure your system is properly maintained.

Conclusion: Ensuring a Safe and Compliant Workplace


An effective LEV system installation is an investment in workplace safety, regulatory compliance, and operational efficiency. From hood positioning to filter quality and duct design, every detail of an LEV system impacts its performance and longevity. Regular servicing and inspection are not just regulatory necessities; they are essential practices to uphold the health and safety of your workforce.

Ensuring that your local exhaust ventilation system is up to standard requires ongoing vigilance and expertise. It's essential to partner with reputable professionals who understand the complexities of LEV systems and can provide the support needed for optimal system performance. Protect your workforce, avoid costly fines, and promote a healthy work environment by ensuring your LEV system installation is up to standard.