Computational Fluid Dynamics, vertical flow through buildings

Typical distribution of pressure in vertical shafts of a skyscraper building during heating period, influence of a shaft pressure reduction

zoom in

In the case of skyscraper buildings, the vertical air flow through entrances, openings in the facade, elevators, staircases, smoke dampers etc. require particular attention.

Due to temperature differences between the interior of the building and the outside air, considerable pressure differences can occur on cold winter days with distinctive negative pressure zones in the lower part and overpressure in the upper part of the building (e.g. in the elevator shafts of the building).

Especially in skyscraper buildings, unfavorable opening situations can occur, resulting in the following unwanted effects.

Common effects are:

• Increased input of cold air in the entrance area
• Odor transmission from kitchens and underground parking lots
• Draughts in office, corridor and entrance areas
• Increased opening forces at doors and windows
• Air flow noises at joints and doors
• Doors slamming shut

The effects are analyzed and optimized using Computational Fluid Dynamics.

As far as possible, Computational Fluid Dynamics tends to limit the vertical flow trough buildings by means of targeted HVAC or structural measures.

Utilizing Computational Fluid Dynamcis, pressure conditions and air changes can be calculated for all zones of the building, e.g. for minimum outside temperature. All facts relevant to this purpose are collected:

For the building, the position and flow resistance of

• Windows
• Doors
• Air spaces

For HVAC

• Pressure maintenance in the staircase
• Measures in terms of fire protection

For usage

• Door opening situations
• Room temperature

Afterwards, typical opening scenarios, e.g. of corridor or elevator doors, are analyzed comparatively using Computational Fluid Dynamics. Thus, limiting operating conditions can both be located and optimized systematically.