Ventilation in a manufacturing building has a harder job than in an office. The heat loads are bigger, the contaminants are more varied, the building rarely stops, and the consequences of getting it wrong land on production rather than just comfort.
We work in manufacturing plants regularly, and the same themes come up on nearly every site.
Process heat is the starting point
In an office, people and solar gain drive the cooling load. In a factory, it’s the process. Ovens, presses, motors, compressors and curing lines all put heat into the space, often in one concentrated area.
That changes the design. You may need higher air volumes, spot ventilation over the heat source, or units sized for a load that has nothing to do with the weather outside. On an aerospace facility in Derby we supplied units with DX cooling and a gas burner, because the process demanded both ends of the range from the same equipment.
Contamination works in both directions
Manufacturing ventilation usually has to manage two separate risks:
- Protecting people from fumes, dust, solvent vapour and welding by-products
- Protecting the product from airborne contamination, particularly in food, pharmaceutical, electronics and coatings work
Those two aims sometimes pull in opposite directions. Extraction protects staff but can pull unfiltered air in through doors and gaps if there’s no matching supply. Getting the supply and extract balanced across a large building is where most problems are solved or created. Our guide to industrial ventilation systems covers the wider system design.
Where product protection dominates, requirements start moving towards clean room territory. See clean room air handling requirements for what that involves.
Pressure regimes
Many manufacturing areas need to be positively or negatively pressurised relative to what’s next door. Paint and finishing areas, food preparation, packing halls and goods-in doors all interact. Doors opening, extract fans starting and shift changes all move the balance around, so controls matter as much as the units. Our article on AHU controls and building management systems explains how the two work together.
Shift patterns and 24/7 running
A plant that runs continuously gives you no natural window for maintenance, and the unit itself has no overnight recovery period. That affects specification: duty and standby arrangements, better access for filter changes, components chosen for longer service life rather than lowest capital cost.
The poultry facility we supplied is a good example of the demands of continuous operation. Two bespoke units at 6.8m³/s each, with LTHW, chilled water and reheat coils, running 24/7 in a building that can’t stop. You can read more on the poultry farm project page.
Replacing units in a live plant
Most manufacturing ventilation work is replacement rather than new build, which means working around production. In practice that means:
- Planning the swap around a shutdown, a shift change or a quiet weekend
- Getting large units into plant rooms that were built around the old equipment, often through restricted access. Our flat-pack AHU approach exists for exactly this
- Keeping temporary ventilation running where the process can’t stop
- Sequencing so the building is never left without the ventilation it needs
We’ve covered the general approach in ventilation for live operational facilities, and it applies as much to manufacturing as it does to airports and hospitals.
Energy and running costs
Big air volumes mean big energy bills. The things that make the most difference on manufacturing sites are heat recovery, EC fans and controls that respond to what’s actually happening rather than running flat out for 24 hours. Our guide to AHU running costs breaks down where the money goes.
How we could help
We design, manufacture, install and maintain air handling units for manufacturing facilities across the UK, including bespoke units where the space or the process demands it. Have a look at our air handling units page or browse our projects.
Get in touch to talk through your site.
Frequently asked questions
Often, yes. Process loads, restricted plant rooms and unusual coil combinations mean off-the-shelf units don’t always fit. Standard units still work well in simpler applications.
In many cases, yes, with careful planning, phased changeovers and temporary ventilation where needed. We’ve done this in live airport and hospital environments as well as factories.
It depends on the process heat load, the contaminants involved and any pressure requirements, rather than floor area alone. A site survey and load calculation is the only reliable way to size it.
