MIL-HDBK-1011/2
Close building spacing may decrease natural daylight and adversely
affect ventilation. Daylighting is not usually a problem for residential
types of buildings in hot climates. Whether the ventilation is affected
depends largely on the direction of the prevailing wind.
4.2.3.2
Reflectance. The reflectance of nearby surfaces, especially
obstructions and ground surfaces near openings, can have a large effect on the
interior temperatures of the building. Reflected light and local heat
sources, such as nearby asphalt pavement, can substantially increase internal
temperatures of naturally ventilated buildings and should be avoided,
especially on the windward side. Refer also to para 4.3.
4.2.3.3
Slope. A sloping site may affect the heat gain of the buildings if
it restricts the orientation of the building and its windows. The optimal
orientation for the long face of a building and for windows is north-south
facing. Sloping sites which require placement of windows to the east or west
should be avoided because they are more difficult to shade.
4.2.3.4
Elevation/Altitude. With increasing altitude, temperature and
pollution decreases; pecipitation (rainfall, snow, and fog), insolation, and
daily temperature range increase.
4.2.3.5
Proximity to water. Proximity to large bodies of water may serve
to moderate temperature extremes because water stores more and radiates less
solar energy than soil. On a smaller scale, ponds or sprays may be used to
provide cooling when located near interior spaces if the climate is not too
humid.
4.3
Landscaping
4.3.1
General Principles. Landscaping may affect the microclimate of the
building site and the air movement in and around buildings. (Refer to
Appendix A, Section 2). For naturally ventilated building sites, landscaping
may be effectively used to provide shade for both the building and for the
surrounding outdoor spaces. Landscaping may also be used to increase
ventilative potential or provide shelter from excessive wind.
4.3.2
The Shelter Effect. Windbreaks can protect both buildings and open
spaces from hot or cold winds. A windbreak of vegetation creates areas of
lower wind velocity in its lee by:
a) deflecting some of the wind over the windbreak and the zone
immediately to the leeward of the barrier,
b) absorbing some of the air's momentum, and
c) dissipating some of the air's directed momentum into random
turbulent eddies.
Vegetation is more effective at absorbing wind energy than solid
objects, such as buildings, which primarily deflect the wind.
4.3.2.1
Effect of the Physical Dimension of Windbreak on Sheltered Areas.
The leeward sheltered area varies with the length, height, depth and density
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