Project Location: Weipa, QLD – Cyclonic Zone C
Introduction
In regions prone to tropical cyclones, such as Weipa (Cyclonic Zone C), designing rooftop equipment requires a deep understanding of wind forces, aerodynamics, and structural integrity. Wind speeds can exceed 200 km/h, subjecting mounted equipment to extreme pressure loads that, if not properly designed, may lead to structural failure, safety hazards, or operational inefficiencies.
This case study explores how Deratec used Computational Fluid Dynamics (CFD) simulations and Finite Element Analysis (FEA) to optimise the wind resistance of a rooftop HVAC system mounted on a 40ft inverter container.
Project Overview
The project involved designing an HVAC system to cool an inverter container while ensuring it remained secure and operational under extreme wind conditions. The Temperzone R32 OPA 1410 Econex Pro rooftop units were selected for their energy efficiency and mounting flexibility. To enhance durability, the units were secured with a custom-engineered steel bracket system, preventing excessive movement or damage during high-wind events.
To validate the design’s structural stability, Deratec conducted CFD and FEA simulations to assess wind pressure distribution, aerodynamic forces, and structural loads acting on the system.
The Challenge
Why Is Wind Loading a Critical Factor?
In cyclonic regions, wind loading is a major concern for rooftop-mounted equipment. The wind pressure exerted on structures is influenced by:
✔ Wind Speed & Direction – Higher speeds generate greater pressure on surfaces.
✔ Building Height & Exposure – The intensity of wind loads increases with height and exposure to open terrain.
✔ Aerodynamic Effects – Wind turbulence can cause vortex shedding, leading to oscillations that weaken structures over time.
✔ Cyclonic Uplift Forces – High-speed winds create a lifting effect on rooftop equipment, increasing the risk of detachment if not properly secured.
In Weipa, which falls under Cyclonic Zone C as per AS/NZS 1170.2, equipment must be designed to withstand wind speeds exceeding 200 km/h, with pressure loads reaching 2.5 kPa (23.7 kN per unit). Ensuring compliance with these stringent standards was a key challenge.
Design and Analysis
1. Wind Load Simulation Using CFD
CFD simulations allowed us to analyse:
✔ Wind pressure distribution across the HVAC unit and mounting structure.
✔ Aerodynamic forces, including drag, uplift, and turbulence.
✔ Potential flow separation points, which could increase structural stress.
Using high-resolution CFD modeling, we simulated wind speeds of 207 km/h to replicate real-world cyclonic conditions and evaluate the structural response of the HVAC unit under extreme loads.
2. Structural Strength Analysis Using FEA
✔ Stress and strain distribution within the HVAC brackets.
✔ Load-bearing capacity under extreme wind conditions.
✔ Factor of safety (FoS) to ensure compliance with Australian standards.
The FEA study confirmed that the steel bracket system had a safety factor of 3.0, meaning it could withstand loads three times greater than expected maximum forces.
3. Optimised Mounting System Design
To prevent wind-induced failures, we designed a reinforced steel mounting system with:
✔ High-strength steel angle brackets, securely fastened to the container.
✔ Aerodynamic positioning to minimise wind resistance.
✔ Additional anchoring points to enhance stability and load distribution.
This optimised design effectively mitigated uplift forces, preventing potential detachment or excessive vibrations.
Assumptions
✔ Wind Speed: 207 km/h (Cyclonic Zone C requirement).
✔ Wind Pressure Load: 2.5 kPa (23.7 kN per unit).
✔ Aerodynamic Behaviour: No significant vortex shedding or excessive drag forces.
✔ Structural Integrity: HVAC unit remained securely fastened with a safety factor of 3.0, exceeding compliance requirements.
By conducting detailed simulations, we eliminated potential failure points and optimised the design for long-term durability under extreme wind conditions.
The Key Results
The project successfully delivered a secure, high-performance rooftop HVAC system that:
✔ Maintains thermal efficiency under harsh weather conditions.
✔ Meets Cyclonic Zone C compliance standards as per AS/NZS 1170.2.
✔ Withstands uplift and lateral wind forces without failure.
✔ Uses a validated, cost-effective mounting solution to ensure long-term stability.
Conclusion
This project demonstrates the importance of wind loading analysis in designing rooftop HVAC systems for cyclonic regions. By leveraging CFD and FEA, Deratec provided a technically sound, cost-effective, and compliant solution that ensures long-term operational stability.
If your project involves wind-exposed structures, our expertise in CFD-based wind analysis and structural optimisation can help ensure your equipment is safe, stable, and efficient.
Get in Touch
Need wind loading analysis for your rooftop equipment or tall structures?
Deratec’s CFD and FEA solutions help you meet the highest safety and performance standards.
📞 Contact us today or visit our website to learn more!
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