Advanced and Robust Analysis of Wind Effects
Air quality is often managed through prescriptive rules, generally in terms of minimum separation distances between the sources and accessible areas. There is generally no consideration in these rules for the potential effect of the pollutant being channelled by the wind for example in a gap between two podiums or entrapment of the discharge within a large catchment due to significant shielding of the source location from the prevailing winds.
Windtech offers performance-based solutions that are able to address not only the above shortcomings but allow for flexibility in the design given the many constraints faced by a designer when choosing to locate the discharge locations for a commercial kitchen, carpark exhaust or a standby power generator.
Windtech’s unique approach includes the provision of initial high-level input at the early design stages based on the local wind climate, the proposed building form and shielding by surrounding buildings and topography. Once the design has been sufficiently frozen, more detailed quantitative studies are undertaken against established exposure standards using only or more of the following methods:
For any of the above techniques, Windtech is able to make recommendations for the improvement and management of exposure levels where required to meet specific regulations for the protection and comfort of the building’s inhabitants and the greater public. The test is repeated to confirm the effectiveness of the mitigation strategies.
Case Studies
An example of an air quality study undertaken using the wind tunnel flow visualization technique is the study of an industrial kitchen exhaust located below a communal terrace. The flow visualization indicates that the discharge tends to be carried up then shears down the façade onto the terrace. The solution involving a canopy over the terrace has been demonstrated to be effective (see the image below).
Figure 1: Testing of the canopy treatment as part of a 2011 flow visualisation study for the exhaust from an industrial kitchen in the Saigon Center, HCMC.
Examples of studies undertaken using the wind tunnel spectrometry technique are the SUNY Optometry Building and the Red Deer Regional Hospital. See images of the wind tunnel models below.
Figure 2: SUNY Optometry, New York, NY
Figure 3: Red Deer Regional Hospital (RDRH) Ambulatory Building, Alberta, Canada
Examples of studies undertaken using the computational fluid dynamics modelling method are the study of various discharges including a standby power generator from the Frankston Hospital in Melbourne, Disney HQ at 4 Hudson New York for the study of the rooftop boiler exhaust stream and the TRX Retail Plot 1, Kuala Lumpur for the study of odour dispersion (see Figures 4 to 6 below)
Figure 4: Frankston Hospital, Victoria, Australia – CFD Model Study for one of the sources
Figure 5: (Left) Disney HQ, New York, 4 Hudson Square, New York – Rooftop Boiler Exhaust Stream Simulation
Figure 6: TRX, Retail Plot 1, Kuala Lumpur – Odour Concentration Contours
Related Articles:
https://windtechconsult.com/john-hunter-health-and-innovation-precinct-jhhip-newcastle-nsw-helipads/
Tall buildings in temperate climates, with proper programming of the floor plan can easily achieve effective natural ventilation in buildings with very little reliance on mechanical ventilation. Natural ventilation not only assists in maintaining air quality but can also assist in providing improved thermal comfort by means of night flushing and/or evaporative cooling.
Windtech Consultants is a pioneer in designing and modelling natural ventilation in tall buildings, having undertaken numerous such studies since the mid-1990s. On-site measurement of bulk flow rates has been undertaken to validate our wind tunnel modelling techniques. In some cases, such as a large office or communal recreational spaces, Windtech provides a more detailed understanding of the air flow distribution within the space can be obtained using high-quality Computational Fluid Dynamics (CFD).
Senior engineers at Windtech have developed an innate understanding of where we are able to tap into regions of significant pressure differential across the external envelope of an apartment to drive natural cross ventilation through the apartment. Due to our extensive experience in collaborating with leading design firms, we have developed innovative methods of leveraging these differential pressures without impacting other building code requirements.
The key is to have an early collaboration with one of Windtech’s senior team members to avoid significant rework of the design and develop the simplest and most cost-effective outcome. If you wish to discuss natural ventilation design for your current project, feel free to reach out to your local Windtech Consultants office via the following web link: Contact us (we have 10 offices around the world and there is one near you).
Sample projects from among the hundreds where Windtech have provided advice in relation to natural ventilation in buildings.
WH504 – 30A-34 Brougham Street, Potts Point
WB537-22 189 Macquarie Street, Parramatta
WA567-42 Tower R3, One Sydney Harbour, Barangaroo
The importance of a safe and comfortable wind environment in the vicinity of new buildings is now acknowledged by project managers and architects alike. A study by Rose and Dolega (2021) involving over 2000 major high street retail outlets in the UK has found that wind is the most significant weather condition to impact consumer purchasing behaviour. Developers are beginning to realise the economic benefits of ensuring a favourable wind environment in areas that involve commercial activities, especially where their success hinges on the success of the retail or commercial tenants. Planning approvals relating to wind mitigations are far more streamlined when the pedestrian wind comfort study is undertaken at the early planning stage. Wind tunnel testing remains the most reliable means of predicting and alleviating wind problems around urban structures. It is possible to achieve similar reliability using bespoke CFD modelling (also offered by Windtech). Another advantage of investigating pedestrian wind comfort early in the design process is that it allows for elegant wind mitigation solutions that are properly integrated with the architecture rather than tacky add-ons.
A recently completed development in Sydney incorporating wind mitigations for al fresco dining areas.
A word of caution when using the cheaper commercial packages as they tend to provide erroneous and misleading guidance, which would frustrate the design process when very different guidance is eventually obtained from wind tunnel tests. Windtech is unique in their ability to offer preliminary desktop assessments that would tend to be far more accurate than the cheaper CFD model studies, due to the depth of experience of their senior staff.
Wind testing that is properly undertaken (refer to the AWES-QAM-01 2019) provides an accurate and definitive assessment of wind comfort conditions prevailing in the critical outdoor areas within or adjacent to the site and collectively create wind resilient communities. Wind velocities are measured in the wind tunnel for areas accessible by pedestrians and occupants. The measured wind conditions are directly compared to comfort criteria that vary, depending on the intended use, as well as against the safety limit.
Testing of wind mitigations is highly recommended as it allows for the verification of the effectiveness of the wind mitigation. This also allows the wind engineer to optimise the extent of wind mitigations. It also enables innovative solutions and informed design choices, while also ensuring compliance with local planning controls.
Windtech is the preferred consultant for pedestrian wind comfort studies by many major developers around the world for the following reasons:
Windtech Director, Tony Rofail recalls an example of a tower development (see below) where Windtech had taken over from another wind consultant; “We were approached by a developer in Melbourne who were faced the prospect of incorporating deeper setbacks of the tower from the edge of the podium, based on advice from their wind engineering consultant. We noted that the podium levels above Ground consisted entirely of carpark levels.
Making these levels porous, resulted in the alleviation of the downwash effects from the tower’s exposure to the prevailing northerly winds and served to provide natural ventilation for the carpark levels. This is a win-win for the client as it meant that no increased tower setbacks are needed as well as savings on the mechanical plant in the carpark floors.”
Windtech have 10 offices around the world to service our clients globally. You may reach us from anywhere by sending details of your project to reception@windtechglobal.com.
References:
Windtech Director, Tony Rofail was commissioned by the Australasian Wind Engineering Society in February 2023 to spearhead the development of this much-needed Quality Assurance Manual.
A committee was formed which consisted of Dr Nick Truong (Windtech director), Dr Ahmed Faheem (Windtech Associate Director) as well as representatives from the Cyclone Testing Station, CPP, Insol, MEL and Mott MacDonald.
The document was completed in January 2024 and was adopted by the AWES Executive Committee in May 2024. The QAM is free for anyone to download from the following link: AWES-QAM-2-2024
This is the first such Quality Assurance Manual and deals with the minimum requirements for full-scale testing of components of building envelopes and architectural features.
Covers testing for intricate or finer details on building envelopes not covered by AS/NZS1170.2 and require full-scale (or in some cases a very large scale) tests. Such elements can include:
Covers testing for façade elements and other objects that are likely to exhibit significant resonant excitation and/or wake interference. Such elements can include:
Covers testing of the functionality of façade components under strong wind conditions. Such elements can include:
This section covers the key procedural details in conducting a wind noise test, such as test configurations, methods of recording the noise levels and spectra, positioning of the microphone etc.
Windtech continues to be heavily involved in the various committees around the world which preside over anything wind engineering related. We are committed to contributing and sharing knowledge to ensure that the wind engineering industry continues to develop progressively. Click here to view our wind engineering services.
If you are working on any projects that could benefit from the capabilities presented in this article, please contact our dedicated wind engineers in our regional offices Sydney & Melbourne, Australia, London, UK, and Mumbai, India. New York & Miami, USA, Dubai, Hong Kong & Singapore, we guarantee to support you wherever you are based.
To get regular updates on news and events, please follow us on our LinkedIn page.
Windtech was commissioned by Health Infrastructure NSW and Multiplex to undertake a holistic assessment to ensure the operational integrity of the helipad infrastructure for the John Hunter Health and Innovation Precinct (JHHIP), Newcastle. To meet this operational need, Windtech conducted the following studies:
Through “Desktop” analysis, we were able to assess the likely impact of the redevelopment of the John Hunter Health and Innovation Precinct (JHHIP), located in Newcastle, on the local wind environment at the critical outdoor areas within and around the subject site, the wind entry effects, and the effect of the helicopter travelling to and from the helipads.
Furthermore, our team conducted detailed evaluations of wind speed and turbulence specific to the Acute Services Building Helipad, identifying potential hazards and implementing tailored strategies to mitigate risks and ensure safer and effective aircraft operations.
Implementing CFD modelling methodologies, Windtech conducted an Air Quality/Pollution Dispersion Study, to analyse the dispersion patterns of helicopter exhaust plumes onto the ASB Building air intakes. This comprehensive assessment assessed the effect of the proposed design on the spread of NOX compounds on and around the site. The cumulative directionally weighted average of the NOX results showed no exceedance at the HVAC intakes of the proposed development. Moderately strong odours were predicted in certain areas and various mitigation treatments were recommended.
Figure 1: Cumulative NOX Contours weighted by frequency of occurrence of each wind direction, Plan View
Figure 2: Cumulative NOX Contours weighted by frequency of occurrence of each wind direction, Eastern Aspect
Figure 3: CO Air Quality Category contours. Cumulative CO Contours weighted by frequency of occurrence of each wind direction. Contours are plotted 1.5m from ground (Left) and 1.5m from floor level of the terraces (Right)
Windtech Consultants are committed to providing accurate and reliable modelling to guide the design of helipads to enable safe and functional operation.
If you are working on any projects that could benefit from the capabilities presented in this article, please reach out to our regional offices Sydney & Melbourne, Australia, London, UK, Mumbai, India. New York & Miami, USA, Dubai, Hong Kong, Singapore, and Toronto, Canada we guarantee to support you wherever you are based.
To get regular updates on news and events, please follow us on our LinkedIn page.
