How to Filter Make-Up Air for Poultry Shed Inlets Without Creating Draft Problems

For poultry sheds, make-up air needs to arrive clean, evenly distributed and without upsetting the shed’s airflow pattern. That can be a balancing act: too much filter resistance can lead to drafts, uneven inlet performance and overworked fans, while too little filtration can leave dust and debris entering through the inlets.

The best solution depends on the shed design, local dust load and how the ventilation system is controlled. In many cases, the answer is not just choosing a better filter media, but also placing the filter in a way that spreads air properly across the inlet area.

Why inlet filtration matters in poultry sheds

Poultry sheds often sit in dusty, windy or crop-growing locations where the air entering through the inlets carries fine particles, feather debris, insects and other airborne material. Filtering make-up air can help reduce the amount of dust entering the shed and protect internal components such as fans, sensors and ducting.

But poultry ventilation is sensitive. If a filter adds too much resistance, the system may draw air harder through certain openings, creating uneven airflow. That can show up as cold spots, uncomfortable drafts near birds, or a visible imbalance across the inlet face.

The aim is not simply to add filtration. The aim is to introduce enough filtration to improve incoming air quality while preserving the airflow pattern the shed was designed to deliver.

Filter types that are commonly considered

Coarse pre-filtration

For many sheds, a coarse pre-filter is the first place to start. These filters are designed to capture larger airborne particles before they reach the intake path or any finer stage downstream.

Coarse filters can be useful where the main concern is large dust, litter fragments and general outdoor debris. They are also often a practical choice where airflow must remain as open as possible.

When selecting a coarse filter, look closely at:

• •the filter face area available at the inlet
• •how quickly resistance is expected to rise in dusty conditions
• •whether the frame can be sealed properly into the housing or inlet assembly
• •whether the product is intended for disposable or washable use

Fine filtration where needed

Some sites need a finer stage, especially where the incoming air carries a heavier particle load or where equipment downstream needs extra protection. In that case, the filter arrangement should be chosen with airflow resistance in mind from the beginning.

A finer filter does not always mean a better outcome in a poultry shed. If the media is too restrictive for the fan and inlet arrangement, the system can become difficult to balance. In practice, it is often better to use a staged approach rather than asking one filter to do everything.

Washable and reusable options

Some filters are designed to be washable - check the product instructions. Where this is suitable, washable filters can be useful in dusty environments, but only if the cleaning method is practical and does not damage the media or frame.

A washable product is not automatically the best option. If washing is difficult, inconsistent or causes distortion, airflow performance can suffer. Make sure the product instructions are followed carefully and that the filter is still sealing correctly after cleaning.

Placement strategies that help avoid drafts

Put filtration where air can spread before entering the shed

One of the most effective ways to reduce draft problems is to avoid forcing all incoming air through a very small opening. A larger filter face area, or a layout that lets air spread before it reaches the shed interior, can help reduce face velocity and pressure drop.

This is especially important when the shed uses inlets that open and close in response to fan demand. If the filter is too small for the airflow path, the inlet can become noisy, uneven or difficult to tune.

Keep the air path smooth and even

Sharp turns, blocked corners and poorly supported filter panels can all create uneven resistance. The result may be that one side of an inlet draws harder than another, which can lead to uneven airflow across the shed.

Try to keep the filter arrangement:

• •flat and well supported
• •sealed around the edges to prevent bypass air
• •matched to the shape of the inlet or intake housing
• •easy to inspect without disturbing the rest of the ventilation system

Avoid placing filters where they will bridge or load unevenly

If dust settles heavily on one part of the filter face, airflow can become patchy. That is more likely when the filter is mounted in a position that faces prevailing wind, a feed area, or a location where dust is constantly kicked up.

In some sheds, moving the filter to a more protected position or using a larger face area can improve loading behaviour and reduce the chance of localised drafts.

Balancing airflow resistance with filtration performance

Every filter introduces some resistance. In a poultry shed, that resistance has to be considered alongside fan capacity, inlet geometry and the way the shed is operated in different weather conditions.

A filter that performs well on paper may still be a poor fit if it causes too much pressure drop in the actual installation. The right choice is the one that supports the ventilation design rather than fighting it.

Points to review with the mechanical services engineer or building owner include:

• •expected airflow through each inlet
• •how much filter area is available
• •whether the filter will be used as a primary stage or pre-filter
• •how the system will be monitored for pressure drop
• •whether the inlet arrangement can be adjusted if resistance rises

If you are working to a ventilation design or maintenance plan, it is worth checking whether AS 1668.2:2024 is relevant to the broader installation, and confirming site requirements with the mechanical services engineer or building owner.

Maintenance checks that keep airflow consistent

The best inlet filter arrangement will still need regular inspection, because dust load changes with season, wind, stocking conditions and local activity around the shed. Inspection frequency depends on the system, site conditions and dust load.

Where gauges are fitted, monitor pressure drop so you can see when the filter is loading up. Follow the filter and equipment manufacturer instructions rather than relying on a fixed replacement schedule.

During inspection, check for:

• •damaged or warped filter frames
• •gaps around the perimeter where air can bypass the media
• •uneven dust build-up across the face
• •signs the filter is restricting airflow more than expected
• •evidence that the inlet is pulling air unevenly from one side

If the filter is repeatedly loading too quickly, that may be a sign the location, pre-filtration approach or face area needs to be reviewed rather than simply replacing the same product again.

Working with the right filter supplier

Poultry sheds are not a place for one-size-fits-all filter selection. The right make-up air filter depends on the inlet design, fan arrangement, local dust conditions and how sensitive the shed is to airflow changes.

A supplier who understands both filter media and practical installation constraints can help match the product to the job, whether you need standard sizes or custom air filters for a non-standard inlet.

If you also need ongoing upkeep, filter servicing and commercial filter servicing can help keep the system operating the way it was intended.

Need help with poultry shed inlet filters?

Total Air Filtration is a family-owned air filter manufacturer and supplier in Hillcrest, Brisbane QLD, established in 2009. We can help you choose or make the right filters for poultry shed make-up air systems, including options that suit your inlet layout and airflow constraints.

Call 07 3800 3448 or request a quote. You can also explore our products or contact us if you want to talk through a specific shed setup.