Engineering simulationHKN / Stack effect
In cold weather, differences in indoor and outdoor air density create pressure differences along a building’s height. We analyse stack effect to coordinate entrances, vertical connections and ventilation.
Outdoors, the lobby, floors and vertical shafts form a connected airflow system. Air movement depends on temperature, height, airtightness and open connections. It can affect door opening forces, cold-air infiltration and air distribution. We assess the whole system and use CFD where a local area requires more detailed analysis.
Building height and floor count, plans and sections, entrance and shaft layouts, door and envelope information. The model also needs temperature conditions, leakage data and ventilation flow rates. We agree the operating conditions to assess.
Pressure profiles, airflow paths and values across selected doors and zone boundaries. We compare the original scheme with proposed measures, identify the most influential air connections and provide findings for architects and building services engineers.
Illustrative study
Compare a direct air connection between the entrance and lift lobby with a separated-zone arrangement. Under identical outdoor conditions, assess door pressure differences and entrance airflow. Then examine the effect of changing airtightness.
Which air connections should change to manage entrance pressures?
No. It originates from height and temperature differences, while its effects depend on architecture, airtightness, entrances and shafts. The study therefore brings several design disciplines together.
Yes. Pressure and temperature measurements, ventilation operating data and the actual condition of doors are useful. They help compare the model with observed building behaviour and assess possible measures.
Tell us which decision you need to check.
Discuss the task with an engineer.
A finished brief is not required.
Attach plans or a model to your email.