Pedestrian wind comfort is an evaluation of how comfortable different activities may be at a given location. The evaluation is essentially a statistical evaluation that may be used to guide the intended use of open spaces in the built environment.
“If you plan a cafe at stree level of your building, are people likely to enjoy sitting there, or will the wind be overwhelming”?
Technically, the pedestrian wind comfort is a combination qualtilative and quantitative methods. A combination of the wind climate and wind environment results in a qualitative description of how often the wind speed is at a given level at every point of interest. A qualitative description of how comfortable a given wind speed is may then be used to obtain a map describing the pedestrian wind comfort.
The wind environment can be thought of as the answer to questions like; If a wind speed of 10 m/s is observed at 10 m height approaching our region of interest what is the wind speed then on the corner of our building where a future café has been planned? The wind environment is typically evaluated for one incoming wind speed, for a number of incoming wind directions, in a number of points of interest within focus area and are then expressed as a ratio between the free incoming wind and the wind in each of the points. All points of interest are typically 1.5 m above the ground. Both Wind tunnel measurements and Computational Fluid Dynamics may be used to obtain the characteristics of the wind environment.
The wind environment needs to be determined for a number of wind directions. For pedestrian wind comfort studies this is typically done for 12-36 different wind directions.
The comfort will naturally depend on the activity being conducted; a person walking fast will tolerate higher wind than a person sitting still for a longer period of time. A number of different international standards may be used when evaluating the pedestrian wind comfort. Due to the qualitative nature of comfort, these all have slightly different thresholds etc. The choice of standard may depend on local guidelines or client preferences.