LEV calculations are everywhere — but understanding is what makes a better engineer.

Every Local Exhaust Ventilation (LEV) system is governed by the same laws of physics.

Whether you're designing ductwork, selecting a fan, balancing a system, carrying out a Thorough Examination and Test, or investigating poor performance, you're applying the principles of fluid mechanics—whether you realise it or not.

Yet many LEV practitioners learn equations long before they understand where they come from.

They learn what to calculate.

But not always why.

LEV111: Applied Fluid Mechanics for Local Exhaust Ventilation was written to bridge that gap.

Rather than presenting fluid mechanics as an academic subject, this book explains the engineering principles behind Local Exhaust Ventilation in a practical, accessible way, showing how physics governs every aspect of airflow, pressure, energy and system performance.

Understanding the Science Behind LEV

Fluid mechanics can seem intimidating.

Terms such as pressure gradients, Bernoulli's Principle, energy conservation, static pressure and velocity pressure often appear in textbooks filled with complex mathematics.

This book takes a different approach.

Written specifically for LEV practitioners, occupational hygienists and ventilation engineers, it introduces each concept from first principles before demonstrating how it applies directly to real ventilation systems.

Every chapter builds logically on the last, helping readers understand not only the equations used in LEV engineering, but the physical behaviour they describe.

Inside You'll Learn About:

• Why every LEV engineer needs physics
  
• Matter, mass and energy
  
• Newton's Laws of Motion and their application to airflow
  
• Air as an engineering fluid
  
• Air density and the Ideal Gas Law
  
• Atmospheric pressure and pressure gradients
  
• Static pressure, velocity pressure and total pressure
  
• Pressure losses within duct systems
  
• Bernoulli's Principle and conservation of energy
  
• How fans transfer energy to airflow
  
• Why friction, turbulence and duct geometry influence system performance
  
• Engineering interpretation of pressure measurements
  
• The scientific principles that underpin LEV design, commissioning and Thorough Examination & Test

Throughout the book, engineering theory is continually linked back to practical LEV applications, helping readers understand what is happening inside a working ventilation system—not simply how to perform calculations.

Why This Matters

Good LEV design isn't about memorising equations.

It's about understanding airflow.

When practitioners understand why air behaves as it does, they become better at diagnosing faults, interpreting measurements, selecting equipment, balancing systems and making sound engineering decisions.

Many of the problems encountered during LEV inspections—poor capture, excessive pressure losses, incorrect fan selection, unstable system performance and ineffective control—can be traced back to a misunderstanding of the underlying physics.

LEV111 provides the engineering knowledge needed to move beyond following design rules and begin thinking like an engineer.

Whether you're new to LEV or have years of practical experience, a solid understanding of fluid mechanics will improve the way you approach every ventilation system you encounter.

Who This Book Is For

LEV111 is essential reading for:

• LEV engineers and designers
• LEV testers carrying out Thorough Examination & Test (TExT)
• Occupational hygienists
• COSHH assessors
• Health & Safety professionals
• Engineering students
• Anyone wanting a deeper understanding of how LEV systems really work

Whether you're preparing for professional qualifications, designing systems, troubleshooting poor performance, or simply wanting to understand the science behind Local Exhaust Ventilation, this book provides the engineering foundation on which good LEV practice is built.

Product Details

Title: LEV111: Applied Fluid Mechanics for Local Exhaust Ventilation (Metric)

Series: LEV Academy Engineering Fundamentals

Format: Digital book (PDF)

Focus: Engineering principles and applied fluid mechanics for Local Exhaust Ventilation

Author: Louise Davies Wood

Published: June 2026

Topics Covered: Fluid mechanics, airflow, pressure, energy, Newton's Laws, Bernoulli's Principle, air properties, pressure measurement and engineering interpretation

Ideal For: LEV practitioners, occupational hygienists, engineers, students and anyone seeking a deeper understanding of LEV design and performance.