Mastering the Calculation of Sand Trap Louvres: A Complete Guide

The world of architectural design and HVAC solutions often brings forth unique challenges. One such challenge, particularly in dusty or desert environments, is the presence of airborne sand and dust. Enter sand trap louvres. These ingenious designs are pivotal in preventing sand from entering ventilation or fresh air intake systems. If you're looking to understand how to calculate sand trap louvres effectively, you're in the right place. In this SEO-optimized guide, we dive deep into the process, ensuring you garner both knowledge and search visibility.

Understanding Sand Trap Louvres

Before diving into calculations, let's define sand trap louvres. Essentially, these are specialized louvres designed to separate and trap sand or dust particles from the air, ensuring clean airflow into buildings. They’re particularly common in regions like the Middle East, where sandstorms can clog and damage ventilation systems.

Importance of Correct Calculation

Getting the specifications of a sand trap louvre right is vital:

  1. Efficiency: Correctly sized louvres efficiently separate sand from the airflow, minimizing maintenance and ensuring clean air intake.
  2. Cost-effectiveness: Overestimating can lead to unnecessary costs, while underestimating can lead to system damage or reduced efficiency.
  3. Optimal Airflow: Achieving the right balance ensures the building receives the required fresh air without the accompanying dust or sand.

Steps to Calculate Sand Trap Louvres

1. Determine the Airflow Rate: Know the volume of air that needs to pass through the louvre. This is typically expressed in Cubic Feet per Minute (CFM) or Cubic Meters per Hour (CMH).

2. Establish the Maximum Face Velocity: Face velocity is the speed at which air flows through the face of the louvre. For sand trap louvres, it's generally recommended to have a face velocity between 1.5 to 2.5 meters/second (m/s) for optimal sand separation.

3. Calculate the Gross Louvre Area: Using the formula: 

​ You can derive the total area needed for your louvre.

4. Account for the Louvre Efficiency: No louvre is 100% efficient. Sand trap louvres typically have an efficiency of around 70-90%. This means only 70-90% of the gross area will be effective in allowing air to pass through. Adjust your calculated area by dividing it by the efficiency (expressed as a decimal). For instance, if efficiency is 80%:

5. Factor in Structural and Aesthetic Considerations: Remember to account for structural components, like mullions and transoms, which can reduce the effective area of the louvre. Additionally, building aesthetics might dictate the shape and arrangement of the louvres.

Key Tips for Sand Trap Louvre Calculation:

  1. Consider External Factors: Local wind speeds, direction, and the frequency of sandstorms can influence the choice of face velocity and overall design.
  2. Maintenance Access: Ensure that the louvre design incorporates easy access for maintenance and sand removal.
  3. Regular Review: As buildings age and external environments change, it's beneficial to review the performance of your sand trap louvres periodically and make adjustments if needed.


Sand trap louvres are crucial components in maintaining the health and efficiency of a building's ventilation system, especially in sand-prone areas. Properly calculating and designing these louvres ensures longevity, efficiency, and cost-effectiveness. Whether you're an architect, HVAC professional, or a building owner, understanding the intricacies of sand trap louvres can greatly benefit your venture. Dive deep, calculate right, and ensure pristine air quality for your spaces.

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