P601 Training Material

Basic LEV Maths – Fan Laws

A Simple Introduction to One of the Most Important Mathematical Principles in LEV   LEVCentral Expert Commentary One subject that many new LEV engineers find intimidating is fan laws. Yet they are amongst the simplest—and most useful—mathematical relationships used in …

Fletcher’s Nomogram for LEV Design

The Slide Rule of LEV Engineering Before Computers, Apps and Spreadsheets   LEVCentral Expert Commentary Before spreadsheets, mobile apps and computer-based duct design software became commonplace, LEV engineers relied on a remarkable graphical calculation tool known simply as Fletcher’s Nomogram. …

The Moody Diagram

An Important Chart in Fluid Mechanics and LEV Design   LEVCentral Expert Commentary If Fletcher’s Nomogram was the traditional graphical calculator for duct pressure losses, then the Moody Diagram is the chart that makes those calculations possible. The Moody Diagram …

LEV Glossary of terms

This is a glossary of basic LEV terms: ACoP –  Approved code of practice. This carries greater legal weight in Great Britain courts than guidance. Aerodynamic diameter – The diameter of a unit-density sphere that has the same settling velocity in air as …

HSE What is Local Exhaust Ventilation – Video

A Simple Introduction to How LEV Systems Protect Workers’ Health   LEVCentral Expert Commentary This short HSE video is one of the best introductory resources available for anyone who is new to Local Exhaust Ventilation (LEV). Produced by HSE, it …

P602 LEV Design – Manual Design Calculation Sheet

A Practical Design Worksheet for LEV Calculations and System Design Exercises   LEVCentral Expert Commentary One of the challenges facing candidates undertaking the BOHS P602 Proficiency Module is translating ventilation theory into practical system design calculations. Whilst software tools and …

Video: How to Use a Pitot Tube

Practical Guidance on Taking Accurate Duct Velocity Measurements LEVCentral Expert Commentary The Pitot Tube remains one of the most important instruments used by LEV engineers, commissioning engineers and occupational hygienists. When used correctly, it provides a reliable method of measuring …

LEV TExT Report Templates – Free Word and Excel Downloads

Why This Resource Matters These free LEV TExT report templates have been developed by OXYL8 to assist LEV engineers in preparing professional Thorough Examination and Test reports under COSHH Regulation 9. Available in both Microsoft Word and Microsoft Excel formats, …

Video – “What Happens When a Centrifugal Fan Runs in Reverse”?

One of the most common faults discovered during LEV commissioning and Thorough Examination and Test (TExT) is a centrifugal fan that has been wired incorrectly and is rotating in the wrong direction. Surprisingly, when a centrifugal fan runs in reverse, …

OMEGA: “Measuring Air Flow in Ducts, Pipes, Hoods and Stacks”

This practical reference guide provides an excellent introduction to one of the most fundamental activities undertaken by LEV engineers and occupational hygienists: measuring airflow. Although produced for the North American market, the principles described are directly applicable to LEV testing …