Maintenance & systems
Fitting LEV into an older workshop is rarely a straight install. The building was not designed around extraction, the processes may have grown up piecemeal, and make-up air is often the missing piece - so a retrofit means assessing what each process emits, designing capture to suit it, and commissioning the result to prove it actually works.
The short answer
Fitting LEV into an older workshop is rarely a straight install. The building was not designed around extraction, the processes may have grown up piecemeal, and make-up air is often the missing piece - so a retrofit means assessing what each process emits, designing capture to suit it, and commissioning the result to prove it actually works.
The detail
An older workshop presents a harder problem than a new-build. Benches, machines and processes have usually accumulated over years, positioned for workflow rather than extraction, and the building's ventilation was never planned around drawing large volumes of air out of it. Dropping a system into that setting well means starting not with ducting but with assessment: what does each process actually emit, how much, and where does it go, so that extraction is designed for the real hazards rather than a generic guess.
Capture then has to be designed to suit each source, because a workshop rarely does just one thing. A grinding station, a welding bay and a solvent-cleaning bench all throw off their contaminant differently and need different hood types, capture velocities and positions. A retrofit that reuses one hood design across mismatched processes will control some and miss others, so the design work is in matching each capture point to the source it serves.
Make-up air is the piece most often forgotten in older buildings. Every cubic metre of air an LEV system extracts has to be replaced, and a tightly sealed or already under-ventilated workshop cannot supply it - so the fans fight a partial vacuum, capture falls short at the hoods, and doors become hard to open. Planning replacement air into the retrofit is what lets the extraction reach the performance it was designed for.
Because so much can go wrong in a retrofit, commissioning is not optional - it is how you find out whether the installed system actually controls exposure. Measuring the airflow and capture velocity at every hood, confirming the system is balanced, and recording those figures as a baseline turns a hopeful installation into a proven one, and gives every future examination a reference point to judge against.
What it means for you
A retrofit done this way slots cleanly into ongoing compliance. Once commissioned to a baseline, the new system joins the fourteen-month thorough examination cycle, gets its place in the maintenance schedule and its own logbook, and is looked after with the same interim checks as any other LEV. The hard work of assessment and commissioning pays back as a system that keeps passing.
It also avoids the classic retrofit failure: extraction that looks impressive, runs noisily, and quietly controls very little because it was sized by eye, starved of make-up air, or aimed at the wrong part of the process. Those systems pass a glance and fail a measurement, and they leave the workforce no better protected than before the money was spent.
Older workshops can be brought up to a genuinely protective standard - it just takes the assessment and design that the building never had, and the commissioning that proves the result. Treated as an engineering project rather than a bolt-on, a retrofit gives an old workspace control that stands up to testing, to inspection and, most importantly, to daily use.
The service behind the guide
Questions
Because older workshops were laid out for workflow, not extraction, and their ventilation was never planned to supply the make-up air a system needs. A retrofit has to work around those constraints.
Yes. Different processes emit different contaminants in different ways, so capture must be designed to suit each source. Assessing what each one emits is the starting point, not the ducting.
It is the replacement air that supplies what the LEV extracts. Older sealed or under-ventilated workshops often cannot provide it, which starves the hoods and undermines capture unless it is planned in.
Very much so. Commissioning measures airflow and capture at every hood, confirms the system is balanced, and records the baseline - which is how you prove a retrofit actually controls exposure.
The system joins the fourteen-month thorough examination cycle, gets a maintenance schedule and logbook, and is kept up with interim checks like any other LEV.
Phoenix Duct Clean · by the numbers
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