Airflow around buildings

8 AIR MOVEMENT AROUND BUILDINGS AND THROUGH A BUILDING ENVELOPE 7.8.1 Airflow around Buildings 

Airflow around buildings consists of natural winds chat travel around and possibly through buildings. Airflow around buildings has two influences on industrial ventilation  

Wind pressures exerted on the exterior building surfaces, which can influence air movement indoors 

The outdoor movement of air contaminants, which can degrade indoor air quality if brought indoors with insufficient dilution. 

This section will describe general features of airflow patterns and then present information on the dimensions and locations of recirculating (stagnant) zones around the building envelope, which determine wind pressures and contaminant dilution. This knowledge allows one to select the locations of stacks and air intakes and to calculate infiltration and natural ventilation rates. 

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Transport of outdoor contaminants is controlled by both the mean motion of winds and dispersal by turbulence. Since airflow around buildings has... 

YSHRAE. 1997. Airflow around buildings. In Handbook Fundamentals, Chapter IS.. American Society of Heating, Refrigeration, and Air Conditioning Engineers, Atlanta. 

Airflow around the building under the influence of natural winds (Section 7.8.1) and... 

One of the effects of airflow or wind around buildings is the exertion of wind pressure forces on rhe surface of the building, which contributes to natural ventilation of the building and infiltration of outside air into the building. As discussed above, pressures tend to be positive (into rhe building) on upwind surfaces and negative (suction) on lateral, downwind, and roof surfaces. 

Figure 7.96 illustrates typical flow patterns for wind directly approaching a building face. Airflow in the undisturbed zone has a speed profile dependent on the terrain roughness and the level of atmospheric stratification. Obviously, most wind will be deflected around and over the building. Wind... 

Natural Ventilation - Ventilation that is created by the differences in the distribution of air pressures around a building. Air moves from areas of high pressure to areas of low pressure with gravity and wind pressure affecting the airflow. The placement and control of doors and windows alters natural ventilation patterns. 

The heated discharge air from the hoist motor is around 45-55 C with an inlet temperature of 40°C. With a VSD the output air temperature could be controlled to a constant temperature by lowering the airflow but this cannot be achieved with a DOL fan motor. With a DOL fan motor the outlet air temperature will vary with inlet air temperature. The outlet air could be used for recycling, heating the inlet air to the mixing chamber or for heating the building, see Heat Recovery Methods. ... 

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