Custom Filters for High-Dust Entry Air in Industrial Doorways

Industrial doorways and open bays can be difficult places to manage air intake. Frequent vehicle movement, changing pressure conditions and awkward openings often mean a standard off-the-shelf filter frame is not the right fit.

For industrial buyers and contractors, the challenge is usually not just capturing dust. It is making sure the filter can be sized correctly, supported properly and serviced without creating avoidable gaps, bypass or access issues.

Why doorway intake points need a different approach

Where an intake point sits close to an open bay, roller door or loading area, the air entering the system can carry a heavier dust load than a typical enclosed plant space. Forklifts, pallet movement, material handling and wind-driven debris can all affect what the filter sees.

That changes the filter design requirements in a few important ways:

• •The opening may not suit a standard commercial or industrial frame size.
• •The filter may need a deeper or stronger support structure to stay sealed.
• •Access for removal and replacement can be limited by shutters, cages, ductwork or equipment layout.
• •The intake may be exposed to uneven airflow, which can shorten service life if the filter arrangement is not matched to the site.

In these situations, made-to-size filters are often more practical than trying to force a standard product into a non-standard opening.

What made-to-size filters solve

Custom filters are useful when the intake point has unusual dimensions, limited depth or a frame that needs to match existing equipment rather than the other way around. They can be made to suit the actual opening and the available support space, which helps avoid gaps around the edge and makes installation cleaner.

For doorway and bay applications, custom sizing can help with:

• •matching non-standard widths and heights
• •working around posts, braces, louvres or guards
• •fitting into shallow or irregular housings
• •reducing the chance of unfiltered air slipping past the frame
• •keeping replacement parts consistent with the site’s existing setup

If you are planning a new installation, it helps to understand the difference between panel filters, bag filters, pleated filters and other formats. Our our products page is a good starting point if you want to compare options before specifying a custom size.

Support matters as much as the media

A filter can be the correct size and still perform poorly if the supporting frame, seal or retaining method is wrong. Doorway intakes are often exposed to vibration, impact and repeated handling, so the supporting structure needs to be considered at the same time as the filter media.

Contractors often need to think about:

• •how the filter will be held in place
• •whether a rigid frame is needed for the opening
• •how the seal will sit against the housing
• •whether the access door or panel has enough clearance for servicing
• •whether the filter can be removed without disturbing nearby equipment

This is one reason many industrial sites benefit from discussing the opening itself, not just the nominal filter size, before ordering replacement units.

Measuring the opening properly

Accurate measurement is the starting point for a custom filter. A measurement taken from an old filter is not always enough, especially if the existing unit has distorted, compressed or been trimmed to fit.

If you are measuring for a replacement, use the actual opening and note the available depth, fixing points and any obstructions nearby. Our guide on how to measure an air filter explains the practical details to check before you order.

Useful information to have on hand includes:

• •overall width, height and depth
• •whether the opening is internal or external to the frame
• •the direction of airflow
• •any clips, rails, channels or hold-downs already in place
• •whether there is room for the filter to be removed straight out, or if it needs to slide or hinge

Where a housing is already installed, a site check can prevent a custom filter from being made to the wrong depth or fixing style. That is especially important around dock doors and vehicle bays where clearances can be tight.

Choosing the right filter type for dusty entry points

The best filter format depends on how much dust is entering, how much space is available and how often the opening is used. In some doorway applications, a coarse pre-filter may be useful to catch larger debris before it reaches a finer stage. In others, a single custom filter stage is enough.

The right selection depends on the system design, but common considerations include:

• •dust type and loading at the entry point
• •how much pressure drop the fan or system can tolerate
• •whether the intake is continuous or intermittent
• •the amount of maintenance access available
• •whether the filter needs a rigid frame or a pleated media construction

If your site uses rated filters, remember that MERV, EN 779 and ISO 16890 do not convert directly. For HEPA applications, H13 filters are at least 99.95% efficient and H14 filters are at least 99.995% efficient at the most penetrating particle size under EN 1822.

For general ventilation projects, site requirements should be confirmed with the mechanical services engineer or building owner, including any reference to AS 1668.2:2024 where relevant.

Servicing, inspection and replacement planning

High-dust entry points usually need closer attention than protected indoor intakes. Inspection frequency depends on the system, site conditions and dust load, so there is no one-size-fits-all schedule.

A practical servicing plan should consider:

• •how quickly visible dust builds up on the filter face
• •whether pressure drop gauges are fitted and can be monitored
• •how easy it is to access the filter without stopping site operations for longer than necessary
• •whether the filter is disposable, replaceable in stages or a product designed for cleaning in line with the instructions

Follow the filter and equipment manufacturer instructions for service and replacement. Some filters are designed to be washable - check the product instructions before attempting cleaning.

If you need ongoing support, our filter servicing and commercial filter servicing information may help with planning maintenance around production and access windows.

When to ask for a custom solution

A made-to-size filter is often the right choice when the intake point is outside standard dimensions or when the site layout makes standard replacement difficult. It is also useful when a contractor needs consistency across multiple openings that are similar, but not identical, from one doorway to the next.

You should consider a custom filter if:

• •the opening is non-standard in size or shape
• •the frame needs extra support or reinforcement
• •the intake is exposed to frequent traffic and dust disturbance
• •existing filters are hard to remove or seal properly
• •the site wants a replacement built around the housing rather than modifying the housing itself

For industrial sites, the goal is a filter arrangement that fits the doorway, supports the airflow pattern and can be maintained without unnecessary rework.

Talk to Total Air Filtration

Total Air Filtration is a family-owned air filter manufacturer and supplier in Hillcrest, Brisbane QLD, established 2009. We can help supply or make the right filters for unusual intake points, including industrial doorways, open bays and other high-dust entry locations.

If you need a made-to-size solution, call 07 3800 3448 or request a quote. You can also contact us or view industries we supply if you are planning a project across multiple sites.