wind orientation in architecture

This fully updated Third Edition covers principles of designing buildings that use the sun for heating, wind for cooling, and daylight for natural lighting.

If buildings are grouped, airflow principles should be used to determine the most suitable arrangement.Where optimal solar orientation and wind orientation are in opposition, solar considerations usually take precedence. Many traditional water reservoirs (Windcatchers tend to have one, four, or eight openings. Using hundreds of illustrations this book offers practical strategies that give the designer Sun & wind diagram. For an elongated building, the largest pressure differences (which drive cross-ventilation) occur when the building is perpendicular to the prevailing wind. The air flows through the house, and leaves from the other side, creating a through-draft; the rate of airflow itself can provide a cooling effect.The windtower essentially creates a pressure gradient to draw air through the building. This design is common in hot, humid climates where floors are elevated to reduce structural rot.When situated next to water, elevated buildings can allow cooler air that has passed over the body of water to enter the building from below. The terrain, surrounding vegetation, and other nearby structures may be used positively to "channel" or redirect breezes into the building. CONTENTS•INTRODUCTION•ARCHITECTURAL CLIMATOLOGY•SIGHT PLANNING•TOPOGRAPHY•PASSIVE SOLAR DESIGN•DAYLIGHTING•VENTILATION•MOISTURE•NOISE CONTROL SYSTEM 3. Windtowers topped with horizontal airfoils have been built to enhance these pressure gradients.Buoyancy is usually not the main effect driving windcatcher air circulationIn a windless environment, a windcatcher can still function using the Heating of the windtower itself can heat the air inside (making it a Buoyancy forces are used to cause night flushing (see below).

In the city of Yazd, all windcatchers are four- or eight-sided. On sloping sites, locations near the crest of the hill on the windward side are desirable. Windcatchers are widely used in North Africa and in the West Asian countries around the Persian Gulf, and have been for the past three thousand years. In general, it is not desirable to site buildings within the wake of surrounding structures or landscaping.

It is possible for a windtower-ventilated building to have very high flow rates; 30 airchanges/hour were measured in one experiment.Other elements are often used in combination with the windcatchers to cool and ventilate: If a windcatcher's open side faces the prevailing wind, it can "catch" it, and bring it down into the heart of the building. A variation of 15 to 20 degrees from true south has little effect on the thermal performance of small buildings. In Windcatchers that cool by drawing air over water use the water as a heat reservoir, but if the air is dry, they are also cooling the air with Simply moving the air also has a cooling effect. Wind velocity increases with increasing height above the ground; elevating the building raises it to an area of greater free wind speeds.Elevated buildings also allow for inlets in the floor of the structure which can permit cool, shaded air to enter the building from below. This cold air then flows from the courtyard into adjacent rooms.A windcatcher can also cool air by bringing into contact with cool Windcatchers are also often used to ventilate lower-level indoor spaces (e.g. Building shape determines the amount of exterior surface area for a given enclosed volume and the length of the interior path of the ventilation air. Ancient Egyptian House miniature showing windcatchers, dating from Model of an Ancient Egyptian house with windcatcher, The windcatcher's effectiveness had led to its routine use as a refrigerating device in Iran. on architectural designs will be examined with a detailed research of buildings under dif-ferent climate conditions. Southern and northern exposures are less difficult to shade, especially with roof overhangs. Architecture hasn't evolved yet to be a natural part of its environment. Wind approaching at an incidence angle of 45 degrees results in interior velocities that are 15 to 20 percent lower than when the wind approaches perpendicular to the face.When windows are in opposite walls, a 45-degree incidence angle gives the maximum average indoor air velocity and provides better distribution of indoor air movement. Valley bottoms should be avoided, since they may have reduced air movement.Street layouts can be used to channel airflow in higher density site planning. Careful selection of building shape and orientation are primary elements in the design of naturally ventilated buildings in Warm/Hot + Wet (Humid) climates. From a painting Suction from the lee side of a windtower is also an important driving force, usually somewhat more constant and less gusty than the pressure on the upwind side. Wind parallel to the ventilation face produces ventilation depending entirely on fluctuations in the wind and is therefore very uncertain.Buildings elevated on columns or lateral walls can have an increased ventilative potential of up to 30 percent over that of buildings on grade. The insulation and heat capacity of the overlying earth maintains the same stable temperature day and night, and as nights in arid climate are quite cold, often below freezing, that stable temperature is quite cool. Wind approaching at 90 degrees is 15 to 20 percent less effective.