When a Resort Needs Custom Air Filters for Obsolete HVAC Equipment

Older resorts often carry a mix of original plant, later upgrades and patchwork replacements. When the air handling equipment is no longer standard, the filter problem usually shows up first: the frame size is unusual, the old filter has been modified to fit, or the equipment no longer matches any common catalogue size.

For resort operators, procurement teams and contractors, the challenge is not just finding a filter that fits. It is working out whether the system needs a true custom filter, a modified standard size, or a review of the whole holding frame before the next order is placed.

Why older resort systems often need non-standard filters

Resorts are rarely simple, single-purpose buildings. Guest rooms, kitchens, laundries, lobbies, conference areas and plant rooms can all run on different HVAC equipment installed across different eras. Over time, that means the site may contain filter housings from multiple manufacturers and several generations of maintenance changes.

A standard replacement may no longer be available when:

• •the equipment is obsolete and the original filter size has been discontinued
• •the holding frame has been altered to suit a previous substitute
• •the filter is an uncommon depth, width or combination size
• •the frame is damaged, bent or fitted with improvised inserts
• •the site has inherited mixed systems from refurbishments or staged expansions

In many cases, the original filter label is not enough to specify a replacement. Printed dimensions, nominal sizes and actual sizes can be different, so the old part number may lead you to the wrong product if the equipment has been modified.

Signs the replacement requirement is not standard

If a resort keeps ordering filters that almost fit, or if staff need to force a filter into position, that is a strong sign the replacement is not straightforward. Other clues include rattling in the frame, bypass dust around the edges, or recurring damage to the media and frame during installation.

What to look for on site

• •no clear manufacturer plate on the air handling unit or filter rack
• •hand-written dimensions on the old filter that do not match the frame
• •mixed filter styles in the same system, such as different depths or frame materials
• •damaged retaining clips, access doors or sealing surfaces
• •evidence that a previous contractor trimmed, packed out or adapted the filter arrangement

Where the system has a pressure gauge or differential pressure display, monitor pressure drop as part of normal inspection. That helps show whether the installed filter is behaving as expected, although a rising pressure reading can also point to a dirty coil, blocked ductwork or another system issue.

How to confirm the right replacement

The most reliable approach is to measure the actual filter opening and compare it with the current filter and the equipment layout. A resort procurement team may have the purchase history, while a contractor may have the mechanical skills, but the most useful information usually comes from a careful on-site check.

If you are unsure how the size should be read, use how to measure an air filter as a starting point. Measure the housing, not just the old filter, and check whether the frame has been altered to accept a non-standard insert.

Information to gather before ordering

• •actual width, height and depth of the filter opening
• •filter type in use now, including frame material and media style
• •any lip, flange, gasket or track details that affect fit
• •whether the filter slides in, drops in, or is clamped in place
• •the equipment make and model if it is still legible
• •whether there is space for the filter to seat without bowing or compression

If the system forms part of a broader ventilation setup, confirm site requirements with the mechanical services engineer or building owner, particularly where AS 1668.2:2024 is relevant to the installation. A replacement filter should suit the equipment and the intended airflow path; it is not enough for it to be close in size.

When a custom filter is the practical answer

A custom air filter is often the simplest solution when the equipment is obsolete but still serviceable. Rather than forcing a nearby standard size to work, a purpose-made filter can be built to match the actual opening and the existing holding arrangement.

That matters on resort sites because access can be awkward, downtime is inconvenient, and repeated “almost right” replacements create extra work for maintenance teams. A properly made custom filter can also avoid last-minute site modifications that may complicate future servicing.

Common reasons to choose custom manufacture

• •the size is no longer sold as a standard item
• •the frame needs a particular depth or edge detail to seal correctly
• •the system uses an uncommon media grade or construction style
• •the unit requires a rigid frame to maintain shape in a tight rack
• •the site wants a consistent replacement option for an older fleet of units

If you are comparing options across different plant rooms or buildings, it can help to review our products alongside the exact filter sizes in use. For sites with varied accommodation blocks, banquet spaces and back-of-house areas, one standard product line may not suit every unit.

Avoiding repeat mistakes on resort sites

Once the correct filter is identified, it is worth documenting it properly so the same issue does not resurface at the next purchase cycle. Keep a simple record of the unit location, measured dimensions, filter style and any special fitting notes. Photos of the installed filter and frame can also help if the original equipment label is faded or missing.

This is especially useful where multiple contractors have serviced the site over time. A clear record reduces the chance of a replacement being ordered from the wrong nominal size, or of a later technician assuming the old modified filter was the original specification.

Good maintenance habits for older systems

• •inspect filters based on the system, site conditions and dust load
• •follow the filter and equipment manufacturer instructions
• •check sealing surfaces and retaining hardware during changeover
• •monitor pressure drop where gauges are fitted
• •replace damaged frames or clips rather than trying to make a poor fit work again

Some filters are designed to be washable - check the product instructions before cleaning or reusing anything. If the unit is part of a specialised ventilation arrangement, make sure the replacement choice is appropriate for the application rather than relying on appearance alone.

Working with an experienced supplier

For resort operators and procurement teams, the best outcome usually comes from treating obsolete filter sizes as a specification issue, not a stock issue. A supplier should be able to help confirm measurements, interpret the existing frame, and suggest a practical replacement path when standard options no longer match the equipment.

Total Air Filtration is a family-owned air filter manufacturer and supplier in Hillcrest, Brisbane QLD, established 2009. We work with sites that need custom air filters for older plant, unusual housings and non-standard replacement requirements, including resort and accommodation applications.

If you already know the dimensions, you can request a quote. If you need help identifying the right option or want to discuss an awkward fit, you can also contact us or explore custom air filters.

For reliable replacement support, call Total Air Filtration on 07 3800 3448 and request a quote.