Tables 1 also show that radiation attenuation parameters R, n, k, a, ax and xa all decreased with wavelength between 0.3 to 0.8 gm and then increased with wavelength beyond these wavelengths for these films. The parameters were found to increase with increasing thickness (Tables 2). In general, these parameters were high in the UV and NIR region but low in the visible region. This seems to confirm the fact that these films are opaque to UV and NIR radiation, but are transparent in the visible.
Again, for Snl2 film of thickness 11.7 x 10-9m, the absorption coefficients are around 6.2 to 3.2 x 106m-1 in the UV and from 1.1 to 3.3 x106m-1 in the NIR. The values of absorption coefficient for MnBr2 and FeCl2 are similar...Read More
Energy analyses of solar faqade collectors and systems behaviour usually come from ideal south orientation of collectors without influence of shading by close objects. However, faqade collectors are more exposed to possible shading problems compared to roof installations. Solar collectors integrated into the building faqade in urban environment could encounter problems of providing sufficient yearly solar irradiation on the surface due to existing or potential future shading by close objects...Read More
Two of the most promising technologies for efficient use of fossil energy are the Combined Heat and Power plant (CHP) and the high performance heat pump. In The Netherlands, several small (micro) CHP plants are available for application in dwellings. In analogy to high efficiency boilers, a so called HRE quality mark is being introduced for units with a Primary Energy Ration (PER) of 140% or more.
Alternatively, state of the art heat pumps achieve a Seasonal Performance Factor (SPF) of 2.5-3 for DHW and 4-5 for space heating. Assuming an electrical efficiency of 50% in the electricity plant, this translates to a PER of 140% for DHW and 220% for space heating...Read More
The detailed evaluation of the 23 questionnaires returned by the LESO-SEB occupants made it possible to get a good understanding of which typical lighting related problems may be bothering occupants in ADS-equipped offices the most. The MAV and nconcerned-values as defined in Subsection 3.1 are used in Table 1 to quantify the annoyance of different typical problems. First of all, we observe that the maximum MAV is 34% and the maximum number of directly concerned occupants nconcerned is 6. These low values underline the general impression that occupant
satisfaction within the examined ADS-equipped is quite good. Furthermore, Table 1 shows that all problems scoring MAVs of 20% or higher are related to situations where too much daylight is bothering the occupants...Read More
An energy balance is applied in each node and is represented by a network thermal resistance as we can see in Figure 2.
1 T я.
Fig. 2. Thermal network for the solar chimney.
Following the methodology reported by Ong  and Duffie and Beckman , the energy balances produce a system of 5 algebraic equations, and such equations can be expressed as the following array (1):
Where column [Tg, b Tg,2, Tw, Tf, b and Tf2], is the unknown temperature vector. It represents the both glass cover temperatures, the metallic vertical plate temperature, and both air fluid temperatures respectively.
The temperature vector is calculated by solving the matrix system...Read More
In order to allow an easy application and implementation of the program, a documentation “solar kit” has been developed.
The “solar kit” includes a guideline document and a standard format for public calls for tenders based on quality and reliability as key-criteria for design and installation. This first outcome can be surely considered a valuable step towards the standardisation of the solar integration procedures, even though many aspects still have to be faced.
The guideline document for the implementation of the Programme is addressed to the jails Directorates and to the technicians who have to arrange the tender and evaluate the proposals.
The main aims of this document are:
• Explaining and making clear the administrative procedures for the Programme implementation;
• Defi...Read More