What Facility Managers Should Ask Before Switching Filter Suppliers

Switching filter suppliers can be straightforward when the right information is gathered first, but it can quickly become disruptive if the new products do not match the existing system. Before you place an order, it is worth confirming the exact filter details, the installation space and how the site tracks replacements so the changeover runs smoothly.

As a family-owned air filter manufacturer and supplier based in Hillcrest, Brisbane QLD, Total Air Filtration works with facility managers, procurement teams and mechanical contractors who need filters that fit properly and arrive with the right specifications. Here are the questions that help avoid delays, returns and guesswork.

Start with the equipment, not the supplier

The first question is simple: what filter does the system actually need?

Different air handling units, fan coil units, ducted systems and cabinet setups can use very different filter sizes, media types and frame designs. Do not rely on a part description alone if the site history is incomplete. Ask for the equipment model, the filter rack dimensions and any previous order records before assuming a like-for-like replacement will work.

It also helps to check whether the filter is part of a staged arrangement, such as a pre-filter and a final filter working together. If the upstream or downstream filter changes, the whole set-up should be reviewed rather than replacing just one layer in isolation.

Useful questions to ask include:

• •What is the exact filter size, including depth?
• •Is the filter installed in a holding frame, slide rail or bag-in/bag-out arrangement?
• •Are there any clearance limits that affect frame depth or handle placement?
• •Does the system require a rigid panel, pleated panel, bag, pocket or carbon filter?
• •Are there notes in the maintenance log showing previous fitment issues?

Check the rating and performance basis

If the site has a specified filtration level, make sure the new supplier is working from the same rating basis. MERV, EN 779 and ISO 16890 do not convert directly, so avoid assuming an equivalent rating without checking the actual product data.

In Australia, some sites still refer to G3/G4/F5-F9 classes from EN 779, even though ISO 16890 is now widely used. If the existing records use an older term, ask the supplier to confirm the product in plain language as well as the rating used on the datasheet. That makes it easier to compare apples with apples.

For higher-efficiency applications, such as HEPA filters, the exact classification matters. H13 is at least 99.95% efficient at the most penetrating particle size under EN 1822, and H14 is at least 99.995%. If that level of detail is relevant to the system, it should be written clearly on the order and verified against the manufacturer’s product information.

If the site falls under ventilation design requirements, confirm the project expectations with the mechanical services engineer or building owner and refer to AS 1668.2:2024 where applicable.

Confirm the frame details before you buy

Frame details are one of the most common reasons a replacement filter does not fit properly. A filter can be the right nominal size and still fail to seat correctly if the frame, flange or sealing arrangement differs.

Ask for photographs of the installed filter, the old label and the rack if possible. This is especially useful where the site has been modified over time or where several building systems use similar filters but different frame styles.

Things to confirm before ordering:

• •frame material, such as galvanised steel, aluminium or cardboard
• •flange style and depth
• •gasket type and position
• •clip, spring or rail fixing method
• •airflow direction markings
• •whether the filter is installed with a knife-edge seal, gasket seal or another arrangement

If the filter is part of a custom or non-standard setup, consider custom air filters rather than forcing a standard product into a frame that was never designed for it. A poor fit can create installation frustration and repeat call-outs even when the filter media itself is correct.

Review the site records before the order is placed

Good ordering starts with good records. If the changeover is being managed by procurement, ask the maintenance team or contractor for the most recent site notes, not just the original purchase record.

Look for details such as:

• •the actual measured size, not only the nominal size
• •the date of the last filter change and any installation issues noted
• •pressure drop readings where gauges are fitted
• •whether the previous supplier substituted a different product
• •whether access is through a ceiling plenum, plant room, roof space or enclosed cabinet
• •whether the site has dust, moisture, mould or salt exposure that affects product choice

Inspection frequency depends on the system, site conditions and dust load. Follow the filter and equipment manufacturer instructions, and monitor pressure drop where gauges are fitted. That approach is more reliable than using a generic schedule that may not suit the site.

If records are incomplete, measuring the existing opening and comparing it with the filter itself is a practical next step. Our guide on how to measure an air filter can help reduce measurement errors before you place an order.

Ask how the supplier wants the order information presented

A clear purchase order reduces back-and-forth and helps the supplier supply the right product first time. Before changing suppliers, ask what information they need to build the order accurately.

At minimum, the supplier should know:

• •the site name and location
• •the equipment type and filter position
• •the measured dimensions
• •the frame style and sealing method
• •the required rating or product type
• •the quantity required for the site or call-off arrangement
• •any special handling or packing instructions

If the filters are being ordered for multiple buildings or plant rooms, it helps to create a consistent naming convention for each location. That makes reordering easier and reduces the risk of the right filter being sent to the wrong area.

It is also worth asking whether the new supplier can match the way your team prefers to order. Some sites need a simple repeat item, while others need site-specific codes, clear labels or staged deliveries. A supplier who understands the site’s ordering pattern can help keep changeovers simple.

Think about servicing, access and future reorders

A supplier change should not only solve today’s order. It should also make future servicing easier.

If filters are replaced by an internal maintenance team or a contractor, ask whether the new supplier can provide clear product identification and practical handling information. That may include direction arrows, frame markings or packaging that suits the installation path.

If the site uses regular servicing support, you may want to combine supply with filter servicing or commercial filter servicing so ordering, replacement and recordkeeping stay aligned. For multi-site portfolios, that can make it easier to keep product details consistent across buildings.

Some filters are designed to be washable, but only check this where the product instructions specifically say so. Do not assume a reusable design based on appearance alone.

Make the handover as smooth as possible

A supplier switch works best when it is treated as a documentation check as much as a purchasing decision. The more precise the information, the less chance there is of downtime, rework or a filter arriving that does not suit the frame or the system.

Before you change suppliers, ask for confirmation on fit, rating basis, frame details and ordering format. If anything is unclear, involve the mechanical contractor or engineer before the purchase is finalised rather than after delivery.

If you need help matching an existing filter or arranging a non-standard size, Total Air Filtration can supply or make the right filters for your site. Call 07 3800 3448 or request a quote. You can also contact us or view our products to see the range we supply.