CFD has been gradually entering the domain of Heat, Ventilation & Air Conditioning (HVAC). As a consequence, the buildings are more energy efficient, safer as well as more comfortable.

Based on the flow simulations one can predict:

  • temperature & humidity level in the building
  • efficiency of smoke removal and fresh air exchange (air residence time)
  • speed of fire spreading

CFD simulations add the most value in the design in case of:

  • non-standard designs that cannot be predicted based on engineering norms and experience
  • high energy-saving or strict air-quality targets that necessitate the knowledge of detailed flow characteristics (e.g. hospital rooms)
  • high cost of trial&error tests – for many existing designs is it faster and cheaper to simulate the air behavior rather than test the HVAC system performance in the reality.

Note that some ascpects of HVAC simulations, for instance for smoke spreading may be used as a substitute for costly tests in real live. This is already outlined in the European [1], and Polish recommendations [2].



The newly built Museum of Modern Art (Muzeum Sztuki Nowowczesnej, MSN) in Warsaw was preparing an exhibition. Some of the workpieces had very restrictive demands for the temperature and the humidity of air. The hosts of the exhibition could test the detailed flow conditions in the room either by adjusting the blowers and direct measurements or resort to the CFD simulations. The latter turned out faster and more cost-effective.

They turned to QuickerSim for help and we calculated the humidity and temperature distribution profiles in the entire hall. The simulations was carried out using standard CFD software appended with an exact model for the transport of water vapor [3].

Interestingly enough, we noticed a sharp relative humidity gradient near to the walls on which the paintings would hang. It occurred due to a change of the air temperature because of extra heat conduction through the walls.

This effect subtle could have been detected by careful measurements instead of HVAC simulations. However, the value of the full-scale picture given by CFD becomes self-evident. If the measurements we taken just a few centimeters further from the wall, the effect would have not been recognized.



[1] P.V. Nielsen , F. Allard, H. B. Awbi, L. Davidson, A. Schälin, Computational Fluid Dynamics in Ventilation Design, REHVA (Federation of European Heating, Ventilation and Air Conditioning Associations)

[2] G. Kubicki, D. Ratajczak, T. Kiełbasa,, Recommendations of CNBOP-PIB W-0003:2016 – smoke venting systems for stairways, Scientific and Research Centre for Fire Protection-national Research Institute

[3] Patrick Ken Amissah, „Indoor Air Quality – Combining Air Humidity with Construction Mositure”, University of Strathclyde, Glasgow, U.K