Climate Zones -Macro and Micro Climate
The purpose of climatic design is to facilitate an increase in the energy efficiency of buildings. Thermal design improves the living and working environment for occupants through ecologically sustainable means. It also seeks to reduce the effect on public health by adverse climatic conditions.
Climatic design issues are now incorporated in Residential planning codes and Building Code of Australia.
According to the BCA (Volume 2) Figure 1.1.4 Australia is divided into eight (8) climate zones for the puposes of thermal design of a building. Table 1.1.2 list climate zones for cities of other various locations.
Because buildings are not fully sealed, outside conditions have a significant influence on the climate inside the building. The building's style, the materials used, the state of repair of the building and whether the building is insulated, air-conditioned or without either, all influence the impact outside conditions have on the climate inside the building.
Macro and Micro Climate
Climate change is the greatest environmental threat the world faces today. It is caused by emissions of greenhouse gases such as carbon dioxide. Carbon dioxide (CO2) is a by-product of our use of energy, and therefore by cutting energy consumption we automatically reduce total CO2 emissions.
More info on Macro-Micro Climate from the University of Strathclyde's Energy Systems Research Unit ESRU's web site.
There are many sources of energy available locally within a building site. These include direct and diffuse radiation from the Sun, air movement from winds and temperature differences.
Buildings designed for climate
Some of the designfeatures are outlined below:
There are many Internet site which identify key actions that can be undertaken to save energy. Actions may be divided up into different areas (such as heating, lighting etc.). In Table 1 below you find some links to Internet sites that will be of interest to you.Table 1
You may search the web if you want to look for additional information.
The "Residential Design Codes of Western Australia" requires buildings
to be design for climate. Protecting solar access for neighbouring properties
is an important design criteria. Excessive shadows should not be cast
onto adjacent properties. The calculation of overshadowing
for particular month and times of the day can be determined from sun charts.
(The sunchart is a map of the sun's path across the sky during the year
and maps out the sun's position as a function of day and time.) There
are two types of sun charts:
Figure 1 & 2 show two typical suncharts for Perth 31.97° south
latitude. These suncharts map out the sun's position in the sky (vertical
and horizontal shadow angles). For the location of the sun's position
you need two coordinates, the altitude (vertical) and the azimuth
(horizontal) angle. The altitude angle (angle of elevation) measures the
sun's location in the sky above the horizon.
The cylindrcal sunchart seems to be easier to use. The University of Oregon has a program that creates cylindrical suncharts for any location on the earth. Use these suncharts to determine the altitude and azimuth angle for your assignment.
Templates will be provided to record the appropriate data (see Table 1). They include longitude and latitude angles for various WA locations.
Table 1 shows the azimuth and altitude angles for Perth at 8 a.m., 12
p.m. and 5 p.m. for a hole year. The data for the month December at 8
a.m., 12 p.m. and 5 p.m. are used in Figer 3 to draw a shadow diagram.
Figure 4 shows how the shadows changed during the year. High building will cast long shadows in the winter month. (Azimuth and altitude angles are taken Table 1.)