Built Environment CFD

CFD is a powerful tool that creates a virtual airflow and thermal model of a building or urban environment to assess and optimise these factors before construction commences.

Modifications to an existing building can also be simulated using CFD prior to any physical alterations. This approach helps to minimize design risks and prevent costly mistakes while allowing innovation.

CFD is now a commonly used tool for assessing atmospheric dispersion of pollutants from stacks, fire safety designs, tunnel ventilation systems, heating ventilation and air conditioning (HVAC) systems within buildings (especially data centres and climate controlled clean rooms such as operating theatres) and to achieve optimum air change rates and thermal comfort levels.

BMT WBM has a rich history of air and thermal flow CFD modelling and offers numerous CFD capabilities in the field of built environment.

Atmospheric dispersion modelling

BMT WBM has extensive experience in assessing a wide range of air quality  issues resulting  from built environment development. These assessments often support occupational health and safety studies in an attempt to reduce associated environmental impacts. Such assessments include dust collection design reviews, temperature rise studies and  exhaust and fume dispersion modelling.  A typical example of this capability can be best illustrated in the design and assessment of stacks and resulting mitigation measures to reduce emissions and their impact on the environment.

BMT WBM assessments consider factors such as topography, solar load, humidity, buoyancy, building effects and atmospheric stability in the modelling which are often poorly treated.  A high degree of competence is therefore required to select the most appropriate model, to specify appropriate input data and most importantly to evaluate the results. 

BMT WBM’s visual 3D CFD results greatly assist designers to make quick and scientific decisions. This saves potential re-construction costs, improved performances and minimized risks during operations.

BMT WBM’s modelling experience included the following service area:

  • Gas dispersion impact from building stacks
  • Fume and Odour dispersion from laboratory buildings
  • Exhaust gas impact on helipads on buildings


Fire & smoke propagation

BMT WBM has specialist CFD capabilities for assisting fire protection engineers to predict the movement of smoke in complex enclosed spaces such as atria, public transportations, concert halls, shopping malls and warehouses. In Principle, CFD modelling provides a means to predict smoke movement without the constraints imposed by simpler modelling techniques.

BMT WBM professionals are experienced to support fire and occupational risk engineers from variety of diverse industry. Our expertise includes the design and assessment of fire wall, ventilation fan design and suppression system design optimization and to reduce the fire related risks and fatal consequences.

BMT WBM’s fire modelling software capability includes ANSYS-CFX, ANSYS-Fluent, FDS, and KFX.

BMT WBM’s modelling experience included the following service area:

  • Fire and smoke propagation from underground car park
  • Fire and smoke dispersion from public transport
  • Fire impact and ventilation study for tunnels
  • Fire impact analysis for office buildings
  • Fire and smoke impact studies for offshore facilities

Air quality and thermal comfort

Within certain built environments it is critical to assess the characteristics associated with  indoor air quality at the design stage. Through the use of advanced CFD assessments, BMT WBM assists designers to maximise their designs for greater performance.  Comfort modelling takes into account factors such as room temperature, humidity and expected occupancy as well as heat loss through doors, windows and walls.

BMT WBM is highly experienced in analysing the performance of both natural and forced ventilation systems in order to determine air quality and occupant comfort levels in public and commercial buildings such as movie theatre complex, train stations, large shopping centres and car parks. BMT WBM’s specialty modelling capability include the following service areas:

  • Air quality assessment for buildings, vehicles and other enclosed spaces
  • Thermal comfort assessment
  • Air quality in clean rooms (operating theatres and research laboratories)
  • Car park ventilation
  • Exhaust and toxic gas ventilation design validation for large ware houses, export shed,  manufacturing plants and large public transportation.
  • Radiation, Solar load, and temperature rise on the buildings

Wind Engineering

Hong Kong has is great necessity to manage environmental effects caused by man made structures. Since the characteristics of it’s climate is subtropical and it is one of the most densely populated cities in the world, it is important that urban designs are optimised with consideration to wind penetration. The key issues are to create and/or sustain an environment that promotes good air movement whilst improving the overall townscape. Such matters include encouraging breezeways, greening and landscaping, podium structures, as well as varying building dispositions, setbacks, height and form profiles.

Air Ventilation Assessment (AVA) play an important role in the overall planning and design process of a development proposal. BMT WBM has a strong engineering analysis capability that utilises advanced  Computational Fluid Dynamics (CFD) technique for such assessments.

Using CFD, BMT WBM has demonstrated the potential to yield accurate solutions based on fundamental physics, detailed three-dimensional modelling and local environmental conditions. BMT WBM’s experienced CFD engineering skills have provided the best tool for carrying out air ventilation assessments in Hong Kong.

BMT WBM’s project references include:

  • Long Ping Station Southern site development, Hong Kong
  • Development of Ming Wah Dai Ha Project at Shau Kei Wan, Hong Kong
  • New Acute Hospital in KaiTak, Hong Kong
  • Immigration office building in Tseung Wan, Hong Kong
  • D&C for Rank and File Quarter for Immigration Department at W Yi Hop Road, Kai Chung, Hong Kong
  • New commercial redevelopment at Granville Road in Kowloon, Hong Kong
  • Planning Consultancy for Redevelopment of Ming Wah Dai Ha project at Shau Kei Wan, Hong Kong
  • Residential Development at Lot P of New Reclamation Area in Areia Preta, Macau
  • Residential Development in Taipa, Macau
  • AVA study for LKF Square development in Macau
  • Residential Development At R. De Luis Gonzaga Gomes, Macau
  • Composite Development At Estrada De Seac  Pai Wan, Cotai, Macau

HVAC design support

BMT WBM’s expertise in CFD analysis has proven to be particularly useful for assisting architects and building service designers to simulate a variety of Heating Ventilation and Air Conditioning (HVAC) systems, where cost containment and energy efficiency are important considerations.

We use CFD to simulation, test and analyse HVAC systems, providing an additional level of detailed insight into the performance of HVAC design, in turn creating an opportunity to mitigate any potential design issues.  We are highly experienced with air conditioning analysis and through the use of advanced CFD analysis we can efficiently predict temperature, relative humidity (RH), smoke distribution and air flow profile in order to better understand flow behaviour inside buildings.

In summary, our professional services will not only help you to design effective HVAC systems, they will also assist you in optimising heating and/or cooling to reduce energy consumption. BMT WBM’s specialty modelling experience include the following service areas:

  • Research laboratory HVAC systems
  • Climate controlled clean rooms such as operating theatres
  • Data Centre cooling analysis
  • Airplane part curing oven design assessment
  • Airplane component manufacturer plant HVAC study
  • Heat exchangers ventilation study
  • Mechanically/naturally ventilated car park design assessment
  • Diesel engine enclosure ventilation study