2.1 SOLAR RADIATION Solar radiation is an electromagnetic radiation from the sun. The wavelength of the solar spectrum on the earth surface ranges from 0.28 microns to 3.0 microns; where a micron is a thousand of a millimeter. The solar spectrum is divided into three; i. The Ultra Violet (U.V) ii. The Visible iii. The Infra Red (I.R) – Only the small section of the spectrum between 0.4 and 0.7 microns is light visible to the eye; waves shorter than 0.4 microns are ultra violet radiation and waves longer than 0.76 microns are infra red. Although the peak intensity of solar radiation is in the visible range, over one half of the energy is emitted as infra red radiation. 2.2 LONGWAVE RADIATION HEAT LOSS Longwave radiation is emitted by the surface of the earth to the atmosphere and to the outer space. According to the Stefan Boltzmann law, the intensity of emitted radiation is proportional to the difference between the fourth powers of the absolute temperature, zero Kelvin of the emitting absorbing points. It therefore depends on the difference between the temperature of the earth’s surface and the absorbing medium atmosphere and outer space. Long wave radiation is also emitted in all direction by the gases in the atmosphere; of this the earth absorbs the downward component
2.1 SOLAR RADIATION Solar radiation is an electromagnetic radiation from the sun. The wavelength of the solar spectrum on the earth surface ranges from 0.28 microns to 3.0 microns; where a micron is a thousand of a millimeter. The solar spectrum is divided into three; i. The Ultra Violet (U.V) ii. The Visible iii. The Infra – Red (I.R) Only the small section of the spectrum between 0.4 and 0.7 microns is light visible to the eye; waves shorter than 0.4 microns are ultra violet radiation and waves longer than 0.76 microns are infra red. Although the peak intensity of solar radiation is in the visible range, over one half of the energy is emitted as infra red radiation. 2.2 LONGWAVE RADIATION HEAT LOSS Longwave radiation is emitted by the surface of the earth to the atmosphere and to the outer space. According to the Stefan Boltzmann law, the intensity of emitted radiation is proportional to the difference between the fourth powers of the absolute temperature, zero Kelvin of the emitting absorbing points. It therefore depends on the difference between the temperature of the earth’s surface and the absorbing medium atmosphere and outer space. Long wave radiation is also emitted in all direction by the gases in the atmosphere; of this the earth absorbs the downward component
ARC-05-5570%20-%20Adanikin%20-%20Recommended%20Sun-Shading%20of%20Eastern%20Elevation%20in%20Akure.docx