Filter Purchasing for Rental Properties: What Landlords Can Specify Without Overcomplicating It

If you manage rental properties, the aim is usually straightforward: keep the air system running properly, make replacements easy to source, and avoid confusing tenants or contractors with overly technical instructions. The good news is that you do not need to turn filter purchasing into a specialist project to get reliable results.

A practical filter specification starts with the basics: the right size, the right fit, and a sensible filtration level for the system and site. Once those are set, maintenance becomes easier to organise and replacements are less likely to go wrong.

Start with what the system actually needs

Before specifying a replacement filter, identify the equipment it is going into. The same building can have different systems across split systems, ducted air conditioning, mechanical ventilation, exhaust units and packaged equipment.

What matters most is the existing filter frame, the slot dimensions, the airflow direction and any space limitations around the filter rack. If the filter does not seat properly, air can bypass around the edges and the system will not perform as intended.

For property managers, the easiest way to reduce mistakes is to keep a simple record for each unit or common system:

• •filter size
• •filter type or style
• •frame depth
• •airflow direction if marked
• •where the filter is installed
• •any notes about access, latches or limited clearance

If you are not sure about the size, how to measure an air filter is a good place to start. For irregular or hard-to-source dimensions, custom air filters can help avoid poor fits and temporary workarounds.

Keep the specification clear, not complicated

Landlords often do best with a short, clear spec rather than a long technical one. A practical purchase note might include the exact dimensions, the preferred filter media type, whether the frame is cardboard, metal or plastic, and whether the filter needs a rigid or pleated construction.

If the building owner or mechanical services engineer has already set a requirement, keep to that. In some buildings, site requirements should also be checked against AS 1668.2:2024 and confirmed with the mechanical services engineer or building owner before changing anything.

For most rental properties, the goal is consistency. If a tenant, cleaner or maintenance contractor can identify the correct filter from a simple label or part description, future changes are easier.

A useful approach is to specify:

• •the exact size, not an approximate size
• •the intended application, such as split system, ducted return air or mechanical ventilation
• •the preferred construction, such as pleated or flat panel
• •any limitations, such as shallow depth or restricted access
• •whether the system needs a replaceable filter only, rather than a washable style

Choose a sensible filtration level for the site

Not every rental property needs the same filter grade. The right choice depends on the equipment, the amount of dust in the area, and how much resistance the system can handle.

In Australia, you may still see EN 779 classes such as G3, G4 or F5 to F9, although that standard has been superseded by ISO 16890. You may also see MERV or ISO 16890 references on products. These rating systems do not convert directly, so it is better to select based on the filter’s intended use and the equipment requirements rather than trying to match one label exactly to another.

If you are supplying filters for a ventilation or air conditioning system, the best option is usually the one that fits the system design and gives dependable particle capture without causing avoidable restriction. A filter that is too restrictive for the unit can create unnecessary strain and may not be suitable for the airflow available.

If the property has a higher dust load, nearby construction, pets, or other site conditions that increase the amount of airborne debris, that should be part of the selection conversation. Inspection frequency should always depend on the system, the site conditions and the dust load, and you should follow the filter and equipment manufacturer instructions. Where gauges are fitted, pressure drop can be monitored to help decide when a replacement is due.

Make replacement easy for tenants and contractors

A good rental property filter plan is one that the right person can follow without guesswork. If a tenant or contractor opens the access panel, they should be able to find a clear label or note that says what fits there.

Simple labelling can save time later. You do not need a detailed technical spec on every filter cover. A short note with the size, filter code and contact for ordering is often enough.

Helpful information to include in a property maintenance file or asset register:

• •property address and system location
• •filter size and style
• •supplier contact details
• •any access instructions
• •whether the filter is disposable or a washable product

Some filters are designed to be washable - check the product instructions before assuming that a filter can be cleaned and reused. If the product is meant to be replaced, do not wash it unless the manufacturer specifically says it is suitable.

This is also where good communication helps. If the property has multiple units or similar systems, it is worth keeping the same naming convention across the portfolio so replacements are easy to identify.

Avoid common purchasing mistakes

The most common filter mistakes in rental properties are simple ones: ordering the wrong size, choosing a product that does not fit the frame properly, or assuming that one filter will suit every system in the building.

Other avoidable problems include:

• •ordering by appearance instead of measured size
• •selecting a filter with a higher resistance than the system can comfortably handle
• •forgetting that access may be tight once the filter is installed
• •mixing up different systems in the same property group
• •assuming a washable product is appropriate without checking the instructions

If a filter is too loose, it can allow bypass around the frame. If it is too large, it may not seat correctly. If it is too restrictive, the system may not be the right match for that product. The safest approach is to match the existing equipment and keep the spec consistent unless the system designer recommends otherwise.

For property managers handling several addresses, standardising on a small range of approved filters can make ordering simpler. You can also work with a supplier who can help identify replacements from a sample or measurement, rather than relying on guesswork.

A practical buying process for landlords

A simple process works well for most rental portfolios:

• •identify the system and the current filter
• •measure carefully or check the existing part number
• •confirm the required fit and style
• •choose a replacement that suits the equipment and site conditions
• •keep a record for next time

If you are not already maintaining a property maintenance list, adding filter details is a low-effort way to reduce future callouts and confusion. It also makes it easier to keep replacements consistent when a tenant changes or a contractor rotates.

If you need help sourcing a standard size or a less common specification, it is worth speaking with a supplier that makes and supplies filters rather than trying to force a near-match into the frame.

Simple support when you need the right fit

Total Air Filtration is a family-owned air filter manufacturer and supplier in Hillcrest, Brisbane QLD. We can help landlords and property managers supply the right filters without overcomplicating the process, whether you need a standard replacement or a custom size.

If you would like help identifying a filter for a property, explore our products, see our filter servicing, or contact us for practical guidance.

To discuss your requirements, call 07 3800 3448 or request a quote.