Climate Zones
September 15, 2012; 9:25 AM
RenovateyourWorld.com
There are four main climate zones in the United States: cool, temperate, hot-arid, and hot-humid. Each zone has different needs and therefore requires different techniques for climate amelioration.
The cool zone has very cold winters and hot summers with a wide range of temperatures, from -30 degrees F to over 100 degrees F in summer. Persistent prevailing winds usually come from the northwest and the southwest. In the cool zone the days are short in winter and the sun is very low in the sky.
The temperate zone has cool and hot seasons that are about the same length. Temperatures are not as extreme as in the cool regions. Seasonal winds blow from the northwest and south. Temperate zones have lots of rain and high humidity. The summers may be hot, heavy, and uncomfortable.
The hot-arid zone is dry, clear, and sunny. The summers are long and hot. The nights cool rapidly as heat radiates from the ground into the clear skies. Winds are generally along an east-west axis, with variations between night and day.
The hot-humid zone is warm and wet. Winds are variable in direction and velocity. Hurricanes are common, their winds often from the east or southeast.
By understanding the subtle differences among zones, you can use supplemental energy-saving techniques in the most effective way. In the hot-humid zone, for example, large trees can be used for protection from the hot western setting sun; however, they should be far enough away from the building so that a hurricane will not blow them down on the house. Also, low trees should be used on the east exposure because of the prevailing hurricane winds.
Cool Zone -- Overhead view: 1. Evergreen windbreak; 2. Garage and unheated storage on north and east sides; 3. Cool summer spot under grove on east side; 4. Outdoor living areas on south and west paved for maximum heat retention; 5.Glass areas on south; 6. Tree to block summer sun; 7. Protective wing wall; 8. Tree to block late afternoon sun. Side view: 1. Roof overhang; 2. Shrubs for extra insulation; 3. Earth berm with evergreen windbreak on northwest; 4. Protective wind shadow.
Cool Zones
In cold areas, keeping warm uses more energy than summer cooling and is the major thrust of energy-saving techniques. Some concern, however, should be given to relief from summer heat. Heavy insulation is mandatory.
Windows on the south should let in sunlight for warmth in winter. On the northwest, berms or evergreen windscreens, or both, should give protection from the prevailing winter wind. Land forms, walls and fences may be used to provide sun pockets and barriers.
For the longest seasonal use, outdoor living areas are best placed on the southern exposure. Deciduous trees or overhangs on the south may be needed for some protection from the summer noonday sun. In some locations, protection on the west from the hot, low summer sun may be necessary. A tree or even a trellis with honeysuckle will work.