As with coniferous plants, wind is deflected in all directions around the canopy mass of a large deciduous tree; some wind is directed below the canopy where wind velocity is intensified between the canopy and the ground. Wind is also a potential asset in most regions. To assist wind exposure, a wall or fence should be designed with generous openings. Similarly, plant materials and other elements of height should be kept low to the south and southwest sides. Figure 3-36
Plants can be arranged in a broad "V" configuration to channel the prevailing wind toward outdoor spaces. Areas of ground cover, low perennials, or shrubs below 2 feet will give maximum exposure to wind. Increased wind speed and shade make the space below a tree canopy feel cooler, an occurrence regularly appreciated by players who seek respite under a tree on a golf course on a hot summer day. During the hot season of the year, air movement enhances the evaporation of moisture from people’s skin and thus gives the perception of cooler air temperatures. As previously discussed, a wall or fence can be designed to direct the wind in different ways around and through an outdoor space. The planned arrangement of vegetation, walls/fences, and landform, either singularly or collectively, can likewise funnel wind toward the house or outdoor spaces. Louvers in a fence may be designed to swivel or turn so that they can be adjusted to affect the size and orientation of the openings. It is best to allow the wind to move across a vegetated surface such as lawn or ground because air temperatures above this type of ground material are comparatively cool. This allows the fence to respond to varying wind directions and velocities. Additionally, wind prevents the air in outdoor spaces from becoming too stagnant. Channeling air movement can further enhance wind exposure. Fences and walls can also enhance exposure to wind. When possible, it is likewise desirable to allow wind to move over water such as a lake, pond, or even small water features such as a pool or waterfall. In summary, numerous techniques can be implemented on the residential site for properly designing with wind. The exception to this occurs in hot, arid climates where hot-season wind can magnify the perception of extreme temperatures rather than diminish them. One is to provide generous open lawn or meadow areas to the south and southwest of the house and in outdoor spaces used in the warm season (Figure 3—34). To take advantage of this possibility on a residential site, deciduous shade trees should be located near the south or southwest side of the house or outdoor space (Figure 3-35). Using some or all of these means for designing with wind will ultimately benefit the quality of a residential site design and its associated enjoyment of use by the homeowners. There are a number of means of capturing and taking advantage of the possible benefits of wind on a residential site. Such an open area will permit the prevailing wind to move toward the house or outdoor
An open lawn area to the southwest of the house will give maximum exposure to prevailing summer wind.