WIND CATCHERS
Sep 26, 2015
WIND CATCHERS
INTRODUCTION
Air movement is a major factor influencing indoor climate and should be considered when planning and constructing buildings. For the purpose of climatic design, only regular winds are relevant. Regular winds can be utilized for cooling. If the temperature of the circulating air is below the indoor temperature, then the cooling effect is obvious.
Wind catchers
Wind catchers are a significant feature in the
traditional structures to ventilate and cool
buildings in hot desert and hot, coastal
regions. Wind pressure forces air down the
wind catcher. Air circulation inside the
building is achieved if there are openings on
the opposite side allowing suction of inner air
by lower pressure.
Roof wind catcher
Also called wind chimney is built onto the
roof. In some places the catchers are
unidirectional and orientated to catch
favourable winds or are facing away from it to
draw cool air from the court yard through
rooms, and expel stale air and smoke. By
change of wind they are anticipated to reverse
their function.
Unidirectional roof wind catcher
Solar chimneys and induction vents
Solar chimneys make use of solar heat to
reinforce natural air convection. A black
coated metal pipe chimney is heated by the
suns radiation and so is the air inside. The
latter then rises taking the interior air up and
out. This system is self-regulating, the hotter
the day, the faster the air motion
SOLAR CHIMNEY
Black coated pipe as solar chimney
Principle of thermic effect
Glazed solar chimney
Principle of thermic effect
A variation of solar chimney with solar air ramp
WIND TOWERS
For architects, the wind is an important factor in the design of a building
Wind's effect on the thermal comfort through convection or ventilation and the penetration of air in interior spaces.
Wind towers as their name implies, are ventilation tools used for obtaining natural cooling.
ORIENTATION & FUNCTION OF WIND TOWER AT YAZD, IRAN
4 DIRECTIONAL WIND TOWERS
WIND CATCHERS(Traditional & Contemporary)
Wind catchers at Yazd.
8 DIRECTIONAL WIND TOWER
WIND CATCHERS WITH EQUAL CANALS
WIND CATCHERS WITH DIFFERENT CANALS
MATERIAL, COLOUR & TEXTURE
Multi-directional roof wind catcher(tower)
Multidirectional wind towers utilize winds from any
direction. Generally, wind towers are square in plan
and have four internal shafts.
The principle involved is to catch an unobstructed breeze at a high level and channel it to areas in the bottom parts of the building. The increased air-velocity supports perspiration and is thus cooling. The ducts are preferably built in a massive way to absorb the heat of the incoming air and not exposed to solar radiation (e.g. northern wall), to enhance efficiency.
Multi-directional roof wind catcher(tower)
plan, section and perspective view
A recessed, horizontal niche on the external wall, e.g. on the floor level and in the roof parapet, creates a slot between two vertical, structural posts. These mid-wall or parapet wind intakes or series of them may allow for enough cross-ventilation through the internal spaces in humid weather, while preserving visual privacy.
Mid-wall and parapet wind catchers
Mid-wall and parapet wind catchers
Wind towers in UK
The simplest design for a wind tower is a vertical construct that projects above its surroundings and has an open top. This will ensure negative pressure and provide suction in all wind directions. If the ingress of rain is a problem, a cover can be placed above the top.
Wind towers at Ionica, Cambridge, UK
Wind towers and wind scoops
Wind scoops can be used in combination with wind towers to create a system by which cool air is provided by wind scoops and warm air is then extracted via wind towers.
Natural ventilation by means of a combination of wind towers and wind scoops can either be via two separate devices, or a single device with both inlet and extract.
Again, the wind scoop should be omnidirectional, and if a combined device is used, a omnidirectional wind tower can also be employed.
Wind scoops at Bluewater Shopping Centre, Kent, UK
Monodraught wind catcher
FUTURE OF TRADITION
Shower Tower, Australia