Cd

owner South East Asia Development Corporation Berhad location Jalan Macalister, Penang, Malaysia latitude 5.2*N

nos of storeys 21 storeys date start 1995

completion date 1998 (March)

areas Total gross area (incl. carpark) 10.900 sq m

Total net area 8.192 sq m nos of carpark bays 94 bays site area 1,920 sq m plot ratio 1:5.5

design features • The propo^d tower on this <■ 21 storeys and contains spaces tor banking had at the ground floor and at level 1 and an auditorium tor meetings and assemblies at level 6 The auditorium is also accessible by a separate external staircase Above this are 14 floors ot office space

The building s design features are as follows

• All office floors (although designed to be air-conditioned) can be naturally ventilated

• The building has wind wing-walls to direct wind to special balconies lone that serve as pockets with air-locks' (having adiustable doors and panels to control the percentage of openable windows) for natural ventilabon This butldmg is probably the first high-rise office that uses wind as natural ventilation for creating comfort conditions inside the building Other claims of 'natural ventilation' in high-rise towers use natural ventilation simply as a source of fresh air supply to the interior and not for internal comfort

• The building was onginally designed for tenants to install their own split-unit air-conditioning as it was perceived that the poor rental rates did not justify the installation of a central system However a central air-conditioning system was subsequently installed

• All the lift lobbies, staircases and toilets have natural sunlight and ventilation making the building safe to use (le naturally lit stairs and lobbies in the event of power failure or other emergencies) and also low energy to operate energy consumption

• The cooling load of the building is 6.000.773 BTU (500 RT)

• The air-conditioning consumption is 126 kWhr/sq m/annum

• The total energy consumption of the building IS 244 kWhr/sq m/annum

• The energy consumption, if naturally ventilated

(ie without air-conditioning) 118 kWhr/sq m/annum.

(Source Ranhill Bersekutu Sdn Bhd)

the wind wing-wall concept

elevation A

section A-A

figure 5 > Shows a single wing-wall option which is more efficient for winds coming Irom inclined incidences than figure 4

On« of the ways in which natural ventilation can improve occupant comfort » passive low-energy cooling of building, is through a direct physiology .u* *** * occupants For example, by opening the windows, we let the wind ,n and ,n **

provide a higher indoor air speed, which make the occupants inside feel coder Tk. - ^ is generally called comfort ventilation. '

Introducing the outdoor air with a given speed into a building may provide a cool, even when the cooling temperature is actually elevated This is particularty true humidity is high and the higher wind speed entering the space increases the rate cf^ * evaporation from the skin of the occupants, thus minimising the discomfort that tfJT* when their skin is wet.

Such comfort ventilation may be desirable from the physiological viewpoint, even wtier outdoor temperature is higher than the indoor temperature, because the upper temp«' ** limit of comfort is shifted upwards with a higher air speed Therefore even if th. - - ' temperature is actually elevated by ventilation with the warmer outdoor air, the effect comfort of the occupants (up to a given temperature limit) might be beneficial

The important factor is the airspeed over the body of the occupants. This air speed car further increased by the greater opening of the windows and also by the use of suchdt, as ceiling fans in closed buildings.

Contrary to popular belief that the incident impact of wind on the externa) wall grv« ventilation, it is in fact the oblique wind with angles of 30° to 60° away from the normal n-l can provide better ventilation conditions in rooms. When the wind is oblique to the buitar-a pressure gradient is created along the windward walls. This pressure gradient can be fuitf-increased by adding a single wing-wall (a vertical projection one side of the wind)

The wing-wall is simply a short wall placed perpendicular to an opening in the building * the orifice leading to the msides of the building), that is used in combination with theonficejs a device like a pocket to collect and direct the greater range of prevailing winds (where these come from a range of incidences) into the insides of the building The device can be used ¡0 enhance the internal conditions of comfort (eg. internal air changes, temperature numiditv etc) The design of this device depends on local wind conditions, the plan depth and buMt fom and would need to be tested by wind-tunnel tests or by CFD (Computational Fluid Dynamic! simulations to ascertain effectiveness, size of openings, control components, wing-wiii s« and shape, wing-wall orientation and location in relation to the built form, etc fifi figure 1 > shows the conditions without the wing-wall Wind A from a perpendicular angle of incidence hits the wall and the orifice The flow that enters the orifice is 'a', which is generally smaller in dimension than the orifice's opening dimension 'x'.

figure 2 > shows the situation when wind comes from an incline incidence to the wall and the orifice The wind B' hits the building's external wall, generating flow b' into the interior Assuming that wind speeds A' and B' are the same, then flow 'b' is smaller than a', since wind B' comes from an inclined angle of incidence figure 3 > shows the situation with the addition of a perpendicular wing-wall. The wall is located on that side of the orifice that should enable it to collect the greater range of prevailing winds Which side of the orifice for the wing-wall to be located depends upon an assessment by the designer of the wind-data of that locality. In this instance, this is assumed to be primarily within 45° incidence from direction 'A' and 8' The flow through the orifice is 'c' which is equal to or greater than flow 'a' or b' due to the wing-wall.

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