Computational Fluid Dynamic (CFD) models to tune Air Changes per Hour (ACH) in industrial buildings

When a scientist or a consultant faces the odour emission inside a building, experiences an uneasy feeling.

impulsion point  In this website you will read information about odour emission in the environment, about olfactometry and dispersion modelling. When a scientist or a consultant faces the odour emission inside a building, experiences an uneasy feeling.

  Efficiency in a ventilation system plays an essential role in the air renovation inside buildings. Verification of the efficiency is a very complex process that requires tools able to predict the behaviour of air or pollutants inside buildings. In this environment, models based on Computational Fluid Dynamic (CFD) become essential, as they help to optimize ventilation systems in industrial buildings.

  The ventilation systems are normally designed by setting a certain number of Air Changes per Hour (ACH), based on the previous experience of the installer and not efficiency criteria  or energy saving. There is a constant trend towards setting a higher frequency of ACH to be on the safe side, however the same affect would be normally achieved with a lower ACH frequency, and this is money.

  Door entrances and exits play a significant role in the verification of the efficiency of a ventilation system. In addition, an adequate attention must be paid to odour emitting sources and common staff working areas.

  Door and window openings modifies the flow pattern inside an industrial building, turning a standard ventilation system into an inadequate and inefficient tool to disperse odours. Also, obstacles inside the building can contribute to a deficient ventilation.

Computational fluid dynamics

  Computational fluid dynamics, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with surfaces defined by boundary conditions. With high-speed supercomputers, better solutions can be achieved.

  CFD models are able to simulate particle/fluid behaviour, both outside and inside buildings, allowing the calculation and quantification of aspects such as air renovation, mean age of air, efficiency of a ventilation systems, patterns of air flow, pollutants dispersion, temperature profiles, etc.

 The company Aqualogy (before Labaqua) offers a service of modelization with a CFD model through the Olfactometry and Modelling Department.

  Read more about this paper in Spanish here.


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Carlos Nietzsche Diaz Jimenez's Avatar

Carlos Nietzsche Diaz Jimenez

Carlos is the editor-chief of and has been in the odour world since 2001. Since then, Carlos has attended over 90 conferences in odour management, both national and international and authored a few papers on the subject. He has also organized a few international meetings and courses. Carlos owns a small company named Ambiente et Odora (AEO). He spends his free time with his wife and his twins, Laura and Daniel, and of course, writing on

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