Feedlot Ventilation

Ventilation is one of the most important considerations when planning a covered feedlot. While it often receives less attention than the structure itself, effective airflow plays a significant role in livestock welfare, operational efficiency and the long-term performance of the facility.

A well-ventilated feedlot helps manage heat, moisture and air quality by encouraging consistent natural airflow throughout the building. Rather than relying on mechanical systems, many covered feedlots are designed to work with prevailing winds and proven structural design principles to create a healthier and more comfortable environment for livestock.

Understanding how ventilation works during the planning stage helps ensure it becomes an integrated part of the overall design rather than an afterthought.

Why Ventilation Matters

Every covered feedlot creates its own internal environment.

Without effective airflow, heat and moisture can build up within the structure, reducing livestock comfort and creating less favourable operating conditions.

Good ventilation helps maintain more consistent environmental conditions throughout the year while supporting livestock welfare and the day-to-day operation of the facility.

Well-designed natural ventilation can help:

  • Improve livestock comfort.
  • Manage heat build-up.
  • Assist with moisture management.
  • Support air quality.
  • Create more consistent conditions throughout the feedlot.
  • Reduce reliance on mechanical ventilation.

Planning for ventilation early allows these outcomes to be incorporated into the overall building design.

Designing for Natural Airflow

The most effective covered feedlots are designed to work with the natural environment rather than against it.

Natural ventilation relies on prevailing winds, building orientation and structural design to move fresh air through the facility. As air enters one side of the building, it flows across the pens before exiting through roof openings or the opposite side of the structure.

Designing for this natural movement creates a continuous exchange of air without relying on complex mechanical systems.

Understanding local wind conditions during the planning stage helps determine how the building should be positioned to maximise natural airflow.

What Building Factors Affect Natural Ventilation?

According to the MLA Feedlot Covered Housing Systems: Best Practice Design and Management Manual, natural ventilation within covered housing is influenced by several connected design factors, including:

  • Building width.
  • Eave height and overall building height.
  • Roof pitch and configuration.
  • Ridge openings.
  • Building orientation.
  • Prevailing wind direction and speed.
  • Nearby buildings, vegetation and other obstructions that may restrict airflow.

This means ventilation performance cannot be determined from one building dimension alone. A wider building, for example, may require greater consideration of height, roof configuration and ridge ventilation to maintain effective air movement through the centre of the structure.

The Role of Ridge Ventilation

Warm air naturally rises.

Ridge ventilation allows this warmer air to escape through openings along the highest point of the roof while drawing cooler air into the building from lower openings.

When incorporated into the overall roof design, ridge ventilation helps promote continuous airflow throughout the structure, supporting more consistent environmental conditions for livestock.

The effectiveness of ridge ventilation depends on a combination of factors, including roof design, building orientation, prevailing winds and the overall dimensions of the building.

How Much Ridge Ventilation Is Required?

MLA’s covered housing guidance recommends a continuous open ridge for naturally ventilated gable-roof buildings. As a general guide, it suggests an opening of approximately 50 mm for every 3 metres of building width, with a minimum ridge opening of 300 mm.

For example, applying this general guidance to a 30-metre-wide building would indicate approximately 500 mm of open ridge. This should be treated as an early design guide rather than a standalone specification, as local climate, building dimensions, roof configuration and wind conditions also influence ventilation performance.

The ridge should also be designed so warm air can escape while limiting the entry of rain. MLA guidance discusses raised or capped ridge configurations that provide weather protection without unnecessarily restricting airflow.

How Building Width Influences Airflow

Building width plays an important role in determining how effectively natural ventilation performs.

As covered feedlots become wider, maintaining consistent airflow across the entire structure becomes increasingly important. Ventilation strategies should be considered alongside building dimensions to ensure air can move efficiently throughout the facility.

Rather than viewing ventilation as a separate design element, it should be considered alongside structural design, roof configuration and building orientation to achieve the best overall outcome.

How Wide Can a Naturally Ventilated Covered Feedlot Be?

The MLA covered housing manual provides general guidance that naturally ventilated gable-roof buildings should typically be limited to around 30 metres in width in most locations. For single monoslope structures, the general recommended maximum span is around 10 metres.

These aren’t universal limits. MLA notes that wider structures may be possible in cooler climates or locations with favourable natural breezes. However, as building width increases, air has further to travel across the structure and maintaining consistent airflow becomes more challenging.

For example, increasing a proposed building from 20 metres to 30 metres wide doesn’t simply create additional covered area. It also changes the distance air must travel, the required ridge opening and the relationship between building width, height and roof design.

This is why decisions about feedlot layout and stocking density should be considered alongside ventilation rather than independently.

Why Building Height and Roof Pitch Matter

Building height influences the volume of air within a covered feedlot and the ability for fresh air to enter through the sides of the structure. MLA guidance notes that increasing eave height can improve ventilation by increasing the area available for air movement and helping reduce restrictions created by surrounding obstructions.

Roof pitch also influences the movement of warm air towards the ridge. Steeper roof pitches can assist buoyancy-driven ventilation by allowing warm air to rise towards the ridge opening, while the overall roof configuration affects how wind moves over and through the structure.

The relationship between width and height is particularly important. A wide building with relatively low eaves may restrict airflow compared with a structure where the height, roof pitch and ridge opening have been designed together to support natural ventilation.

These dimensions should therefore be considered as part of the complete structural and ventilation design rather than selected independently.

Allowing for Surrounding Buildings and Obstructions

The building itself is only one part of the ventilation equation. Nearby structures, trees, earthworks and other obstructions can change wind patterns and reduce the amount of air reaching the sides of the feedlot.

MLA guidance recommends considering the surrounding environment when positioning covered housing. Where buildings are positioned close together, sufficient separation is important so one structure does not significantly restrict airflow to another.

This makes site selection and building orientation important early design decisions, particularly where future expansion or additional covered pens are planned.

Building Orientation Supports Ventilation

Ventilation begins long before the roof is designed.

Selecting the right building orientation allows a covered feedlot to take advantage of prevailing winds and local climatic conditions.

Positioning the structure correctly can significantly improve natural airflow while helping reduce heat build-up throughout the day.

Building orientation should always be considered together with site selection, roof design and structural engineering to create a complete ventilation strategy.

You can learn more about these considerations in our Feedlot Orientation guide.

When Is Natural Ventilation Appropriate?

Natural ventilation can be highly effective where the site has suitable prevailing winds, and the building width, height, orientation and roof configuration are designed to support consistent airflow.

More detailed ventilation assessment may be appropriate where the proposed structure is particularly wide, surrounding buildings or vegetation restrict airflow, the site experiences low wind speeds, local climatic conditions create additional heat or moisture challenges, or the proposed design falls outside commonly used natural ventilation parameters.

In these situations, ventilation should be assessed alongside structural design and the operational requirements of the feedlot rather than relying on a general rule of thumb. Specialist environmental or ventilation advice may also be required for more complex conditions.

Planning a new covered feedlot? Talk to TechSpan early about your proposed site, building dimensions and operating requirements. We can help consider how building width, height, roof configuration and orientation work together before the structural design is finalised.

Ventilation and Livestock Welfare

The purpose of ventilation extends well beyond moving air through a building.

Consistent airflow helps create an environment that supports livestock comfort by managing heat, moisture and overall air quality. These conditions contribute to a more stable environment throughout the feedlot and support efficient day-to-day operations.

Effective ventilation works alongside shade, stocking density and overall feedlot design to create infrastructure that’s designed around livestock welfare rather than simply providing weather protection.

Bringing Ventilation Together

Successful feedlot ventilation isn’t achieved through a single design feature. It’s the result of multiple planning decisions working together.

Site selection, building orientation, roof design, ridge ventilation and structural dimensions all influence how effectively air moves through the facility. Considering these factors as part of an integrated planning process helps create covered feedlots that provide more consistent environmental conditions while supporting livestock welfare and long-term operational performance.

Designing for natural ventilation from the outset creates a stronger foundation for every other aspect of feedlot performance.

Other Resources You May Find Helpful

Ready to Plan a Better Ventilated Feedlot?

Effective ventilation begins long before construction starts. By considering airflow during the planning and design stage, you can create a covered feedlot that supports livestock welfare, operational efficiency and long-term performance.

At TechSpan, we design covered feedlot solutions that integrate natural ventilation with structural design, helping create facilities that work with the environment and the way your operation functions.

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