Solar light pipes are effective method to induce sunlight into the room need to be illuminated to improve vision quality.
This paper presents the results of monitoring a small solar light pipe located inside a windowless test box of about
0.22m3.The light pipe is 720mm long with the diameter 180mm.The average reflectivity of the internal surface is
0.82.The system has been monitored with luminometers to evaluate the distribution of the luminance on a working-plane
under sunny conditions, cloudy conditions and overcast conditions. All the luminometers are automatic digital
equipments, according with CIE photopic standard. The solar light pipe used in the experiment achieved minimum
illuminance of 140lx overcast sky and achieved maximum of 1657lx under sunny condition. At the corner, the
illuminance value decrease rapidly.The experimental results showed that uniformity ratio of illuminance of the light pipe
variable with the sky conditions. Uniformity ratio of illuminance was 0.48 under overcast conditions, 0.44 at cloudy
conditions, and 0.83 at sunny conditions in the middle in the test box. Compare the experimental results of sunny
conditions with the values of overcast conditions, the difference is the intensity of the illuminance under sunny
conditions was stronger and evenly than under the cloudy conditions.
Experimental investigations on three different sunlight captures with diameter 150mm, 212mm, 300mm were carried out
under different conditions such as sunny conditions, cloudy conditions and overcast conditions and the two different size
solar light pipes with diameter 360mm and 160mm under sunny conditions. The illuminance in the middle of the
sunlight capture have relationship with its size, but not linear. To improve the efficiency of the solar light pipes, the
structure and the performance of the sunlight capture must be enhanced. For example, University of Science and
Technology Beijing Gymnasium, Beijing 2008 Olympic events of Judo and Taekwondo, 148 solar light pipes were
installed with the diameter 530mm for each light pipe. Two sunlight captures with different shape were installed and
tested. From the measuring results of the illuminance on the work plane of the gymnasium, the improvement sunlight
captures have better effects with the size of augmenting and the machining of the internal surface at the same time, so
that the refraction increased and the efficiency of solar light pipes improved. The better effects of supplementary lighting
for the gymnasium have been achieved.
The survey mainly concerns the use of the external surface color of buildings in Beijing. The color parameter values of
the external surface of buildings color are accessed through contrasting with the Chinese Standard Color Chip on-site.
Hue, lightness and chroma are analyzed to research the color of the external surface of buildings. The data provide a
basis for the advanced research of the energy consumption of buildings. Using the color reduced the energy consumption
of buildings; especially in summer air-conditioning energy consumption is of great significance.
Diffusers are important parts of a light pipe which can diffuse light evenly to the place need to illuminate. The lamphouses
used in the experiment were two ultraviolet radiation lamps with the power of each lamp 8W and main
wavelengh was 365nm. The ultraviolet intensity on the surface of the catalyst was about 120μW/cm2. The experiments
also showed that diffusers without photocatalysis could reduce the fraction volume of SO2 in a little box of 0.1 m3
volume made up of stainless steel from 1.0 × 10-6 to 0.36 × 10-6. Diffuser coated with photocatalysis within 1h SO2
fraction volume decomposed from 1.0 × 10-6 down to 0.25 × 10-6 with faster and more complete degradation of SO2. The
experimental results showed that the performance of photocatalysis combined with diffusers of light pipe had better
effect in a small space.
KEYWORDS: Light sources and illumination, Solar energy, Diffusers, Buildings, Sun, Diamond, Solar radiation, Automatic tracking, Roads, Energy efficiency
Natural light is very important element in the quality of vision. Solar light pipes are effective method to induce
sunlight into the room need to be illuminated especially for corridor, some places natural sunlight cannot arrive. Solar
light pipes are also effective ways to reduce electricity consumption for lighting; it can transmit sunlight from outdoor to
the room without generating excessive heat. The performance of two top lighting solar light pipes and one side lighting
solar light pipe were investigated at the same time under sunny conditions in winter in Beijing. The results showed that
side lighting solar light pipes have better performance than that of top lighting one. Side lighting light pipe has better
performance than top lighting light pipe if there are no shelters around the top dome under sunny conditions in winter in
Beijing. Solar altitude is the main reason to give an effect on the performance of light pipes. The experimental results
also showed that top lighting solar light pipes with "snow type" diffuser has better performance compare with the
"diamond type" one. Solar azimuth can also affect the illuminance for whole day to all solar light pipes. So if the
sunlight collector can following with the sun, this problem can be resolved, that is, automatic sun trackers are needed,
but the cost will become too much at the same time. Different regions and different seasons had to select different types
of solar light pipes to achieve maximum output of illuminance in the room. Design of the solar light pipes must adjust
measures to local conditions. Solar light pipes will be popularized in the near future in China because have many
advantages to improve energy efficiency in buildings.
KEYWORDS: Buildings, Thermography, Thermal effects, Infrared radiation, Infrared imaging, Energy efficiency, Temperature metrology, Solar energy, Solar radiation, Roads
Architecture colour is an important part in urban designing. It directly affects the expressing and the thermal effect of
exterior surface of buildings. It has proved that four factors affect the sign visibility, graphics, colour, lighting condition
and age of the observers, and colour is the main aspect. The best method is to prevent the exterior space heating up in the
first place, by reflecting heat away room the exterior surface.The colour of paint to coat building's exterior wall can have
a huge impact on energy efficiency. While the suitable colour is essential to increasing the energy efficiency of paint
colour during the warm summer months, those products also help paint colour efficiency and reduce heat loss from
buildings during winter months making the interior more comfortable all year long. The article is based on analyzing the
importance of architecture color design and existing urban colour design. The effect of external surface colour on the
thermal behaviour of a building has been studied experimentally by Infrared Thermographic method in University of
Science and technology Beijing insummer.The experimental results showed that different colour has quietly different
thermal effect on the exterior surface of buildings. The thermal effect of carmine and fawn has nearly the same values.
The main factor which is color express, give some suggest ting about urban color design. The investigation reveals that
the use of suitable surface colour can dramatically reduce maximum the temperatures of the exterior wall.
Keywords: architectural colour, thermal, thermographic
Solar light pipe combined with Photocatalysis to depredate formaldehyde under cloudy conditions in summer were
tested in Beijing. The solar light pipe used in the experiment is a straight solar light pipe, which is 550mm long, with
diameters of 280mmmm Degussa P25 titanium dioxide ("Degussa", Germany) as photocatalyst was coated on the surface
of the emitter of the solar light pipe. The test chamber made up of stainless steel is 0.1m3. The experiment results
showed obvious effect on decomposing formaldehyde of solar light pipe combined with Photocatalytic under cloudy
conditions. The volume fraction of formaldehyde reduced from 1.0x10-6 to 0.16x10-6 during 35min and the value
reduced from 1.0x10-6 to 0.10x10-6 during 60min under cloudy conditions. The experiment showed that Photocatalytic
by the radiations of sunlight under sunny conditions also has good effect for air cleaning.
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