The principle differences affecting smoke control for a super tall building are the increased contribution of height to stack effect
and wind effect.
The form of the architecture exploits passive methods of cooling through shading, thermal mass, stack effect
ventilation and prevailing winds.
Higher air temperature in the indoor space means higher infiltration rate due to the stack effect
, which promotes more outdoor air with low moisture content to penetrate indoors and increases the real air dryness.
The stack effect
and the reverse stack effect
occur due to temperature differences between the building and outside air.
The only caveat is that the double facade runs around the building, so it is slightly difficult to imagine the stack effect
of rising warm air being fully effective on the north facade.
Stair pressurization can be very difficult in tall buildings due to stack effect
and floor-to-floor variations in flow resistance.
The natural ventilation mode was a significant driver in refining the building's form and skin, and following extensive CFD and wind-tunnel modelling it has been proved that, as the atria cut across the high and low pressure zones created by the curved form, a pressure gradient is created that will improve cross ventilation between two-pack atria, and boost the natural buoyancy of the stack effect
through the six packs.
The upward force experienced by the lighter, hot gases is often referred to as stack effect
or chimney effect, and it can be a major factor in determining the route that smoke will take during a high-rise fire.
The outer rainscreen of 10mm toughened glass has a 103mm cavity behind, vented to create a stack effect
, and an inner layer of double-glazed units and insulated aluminium-faced panels.
This difficulty is compounded by the number of occupants in these structures, the stack effect
and fire fighting operations, as well as changing demographics, and risk perception and human behavior in a post September 11th environment.
The courtyard produces a stack effect
through its glass roof that is opened to allow the escape of hot air, and hence initiate air movement inside the house.
Environmental considerations encompass natural ventilation through the stack effect
, a concrete structure to increase thermal mass and the use of river water as a cooling agent.