Building simulation for energy efficient solar shading

The external horizontal shading device is an important climatic design element in the tropical climate. According to the revi ew, little is known about the in fluence of external horizontal shading device on reducing the solar heat gains, daylight penetration and the building energy consumption. Another important aspect is that the review on energy audits indicated a high intensity of energy consumption (an average of 269kWh/m2) for office buildings in Malaysia. However, significant energy savings can be achieved in buildings if they are properly design and operated. Therefore, it is important to investigat e the above interrelated issues to determine appropriate solar shading design strategies for the corresponden ce climate conditions. Also, early design decisions are the most effective than maki ng changes at later stag es after construction, which is time consuming and costly. According to the literature review, energy perfor mance of high-rise building is influenced by several design variables. The best option to optim ize the total building energy consumption is to test the number of design alte rnatives, which is time consumi ng and laborious approach. The other way of dealing with the problem is by varying one variable at a time and keeping the others fixed at reasonable practical values in order to de termine the effect of the particular variable on the energy performance of the building

Impact of solar shading geometry on building energy use in hot humid climates with special reference to Malaysia

External solar shading devices can substantially reduce the cooling load of buildings and large energy savings can be achieved. Hence, intercepting the radiant heat wave before penetrating to the internal environment through envelope openings is the main criterion in designing solar shading. In hot and humid climate, one draw back of using shading devices is the risk to reduce daylight level thus increases in use of artificial lighting. Therefore it is important to understand the magnitude of energy consumption for cooling and lighting when shading devices are adapted in order to analyze optimum shading as energy conservation option in high-rise office buildings. In other words, little is known about the relationship between energy use and external horizontal shading device geometry. In an attempt to elucidate these complex relationships, a simple experiment of an office room is carried out using dynamic computer simulation program eQUEST- 3 (DOE 2.2). The study indicated depth of the external horizontal overhang can be manipulated to obtain an optimum energy use in high-rise buildings. The results showed that correlation between overhang depth and energy is an important aspect compared to correlation between overhang depth with building cooling loads and daylight level, especially in tropical climate conditions

Mitigating Thermal/Solar Heat Gains on Pavements and Its Influence on the Environment

With the vast quantity of natural vegetation being replaced by heat absorption materials due to urbanization, incident solar radiation is seen to be one of the most prominent heat sources. This increases the storage of sensible heat on these materials which accumulates heat impinged on the surrounding surfaces and is entrapped within the urban canyon. A large percent of the urban fabric is seen to be covered by pavements. It is therefore likely that the outdoor thermal environment is most influenced by the surface temperature of pavements increase the overall air temperature as well as the surface temperatures of the wall – hence temperature transfers to the interior, contributing to the operational indoor temperatures. This paper presents a review on paved surfaces aimed at studying the process of thermal heat gains of pavement materials with respect to their surface temperature under continual exposure to solar radiation. An experiment was carried out on three pavement materials to determine its surface temperature during the whole period of the day. Findings show excessive heat on paved surfaces especially during the day. Cool pavements (Porous/ high solar reflectance) however were significantly lower in surface temperature than the conventional impermeable pavements for all paved materials sampled because of its high reflectance and porous nature. This review analysis shows that an improvement on the thermal properties of outdoor spaces can be expected if the solar reflectance of paved surfaces is increased by retrofitting and the porosity be a key feature on the surface of pavements. Keywords: Pavements, Heat gain, Surface Temperature, Solar Radiation.

Fit für die Facharbeit. Ein neuer Kurs im Angebot der Universitäts- und Stadtbibliothek Köln

In dem Aufsatz, der in der Zeitschrift ProLibris (Heft 2/2008) erschienen ist, wird die Entwicklung eines neuen Schülerkurses an der USB Köln beschrieben - von der Konzipierung über die Vorbereitung und die Durchführung bis hin zur Evaluation. Um eine konzentrierte und effektive Planung durchführen zu können, wurde das "Projekt zur Förderung von Informationskompetenz für Oberstufenschüler" im Frühjahr 2007 ins Leben gerufen. Dieser Kurs ist speziell auf Schülerinnen und Schüler zugeschnitten, die in der Jahrgangsstufe 12 die Facharbeit schreiben. Auf ca. 10-15 Seiten sollen die Schülerinnen und Schüler ein individuelles Thema abhandeln, etwa einer Seminararbeit an der Universität entsprechend. Es gilt, Informationsbedarf zu erkennen, kompetent und effizient zu recherchieren und das richtige herauszufiltern und in die eigene Arbeit bedarfsgerecht zu integrieren. Daran anknüpfend ergibt sich eine gute Gelegenheit, den Schülerinnen und Schülern eine große wissenschaftliche Bibliothek zu zeigen und auf die formale und sachliche Literaturrecherche einzugehen. Das Neue an dem Kurs ist, dass die Schülerinnen und Schüler entsprechend des Prinzips der "learning library" zunächst ohne vorherige Erklärungen im Online-Katalog der USB Köln recherchieren und dann feststellen, dass Erklärungen nötig sind, um effektiv bessere Ergebnisse zu erzielen. Die Erläuterungen zu den Recherchetechniken und zum Online-Katalog der USB erfolgen also erst nach der selbständigen Suche. Dadurch wird ein größeres Interesse und höhere Konzentration bei den Teilnehmern erreicht. Im Anschluss an die Recherche findet ein Rundgang durch die Bibliothek statt, bei dem die Schülerinnen und Schüler die Gelegenheit haben, die recherchierten Bücher auch am Standort zu finden und in die Hand zu nehmen. Die Schülerinnen und Schüler lernen die Räume kennen und erhalten Erklärungen zu den Ausleihmodalitäten. Der Kurs dauert 90 Minuten und wird von zwei Diplom-Bibliothekarinnen durchgeführt. Ergänzend zur Beschreibung des Kurses werden die Erfahrungen eines Lehrers mit der Vermittlung von Informationskompetenz dargestellt, und in einem Interview sind die Meinungen einer Lehrerin und einiger Schüler zu dem Kurs "Fit für die Facharbeit" abgedruckt

A quantitative approach to behavioural analysis of drivers in highways using particle filtering

The analysis of the driving behaviour is a challenging area in transport that has applications in numerous fields ranging from highway design to micro-simulation and development of advanced driver assistance systems (ADAS). There has been evidence suggesting changes in the driving behaviour in response to changes in traffic conditions, and this is known as adaptive driving behaviour. Identifying these changes, the conditions under which they happen, and describing them in a systematic way would contribute greatly to the accuracy of micro-simulation and more importantly to the understanding of the traffic flow, and will therefore pave the way for introducing further improvements in the efficiency of the transport network. In this paper adaptive driving behaviour is linked to changes in the model parameters for a given car-following model. These changes are tracked using a dynamic system identification method, namely unscented particle filtering

Implementation of solar chimney in orang asli settlement in Bukit Lagong Selayang

In compliance with the Malaysia Housing Policy, providing adequate, affordable and quality housing for all is the major goal. The case study house for the study is in the existing settlement for Indigenous people located at Bukit Lagong, Selayang, Kuala Lumpur which was built under the 7th Malaysia Plan (1996-2000). However, the poor thermal performance of the existing house does not satisfy the occupants and cause most of the occupants rather carrying out the daily activities outside the house during the daytime. A field measurement was carried out from 12am of 4 March 2011 to 11pm of 5 March 2011 in order to obtain the real-time data and compared with the CFD simulated result. The experiments followed by introducing solar chimney at the simulation model and examine the result of the thermal performance. The findings show that the thermal performance of the mean air temperature and mean air velocity of the indigenous house has been improved after introducing solar chimney by 2.6% and 15% respectively at the hottest hour compared to the measurement results. This has shown that the solar chimney is useful and functions as the stack ventilation tool in the tropics

Empirical validation of daylight simulation tool with physical model measurement

Problem statement: In recent years, daylighting simulation tools have been increasingly used by many architects, engineers and researchers to evaluate the day lighting performances of building design. Most of these tools employ CIE sky models for simulation. However, the accuracy and applicability of these tools for tropical sky are doubtable. The aim of this study was to validate the computer simulated result with scaled physical model results measured under real tropical sky. Approach: Daylighting model was constructed using scaled physical model to be tested under real sky measurement. The same model was configured in Desktop Radiance 2.0 to perform day lighting simulation experiments. All the measurements were carried out under intermediate and overcast tropical sky conditions in Malaysia; while related CIE sky conditions were used for simulations. Results: Due to the CIE sky conditions are very dissimilar from the actual tropical sky; simulated absolute value results such as external illuminance, absolute work plane illuminance and surface luminance recorded high mean differences from the measured results, with 81.63; 71.06 and 49.71%, respectively. However, relative ratios such as Daylight Factor (DF) yielded mean difference of 26.06% and luminance ratio was 29.75% only. The average mean difference was 44.37%. Conclusion/Recommendations: To compare the performances, relative ratios such as DF and luminance ratio showed better accuracies. For future research, validation on other parameters can be performed such as orientations, angle of the overhang, glazing, window sizes, colors, environment settings and electric lighting

Daylight performance through different types of glazing in the tropics

Having glazing on buildings will allow natural daylighting in a room. There are four types of glazing which are commonly used in the market today: Clear, light green, bronze and black float glass where tinted glazing will provide shading to the interior. These four glass are being tested using Integrated Environmental Solutions Virtual Environment (IESVE) software with different proportion to investigate the influence of arrangements of glazing to permit daylight and to serve as shading device. There are 40 combinations of different glazing proportion tested in the simulation. The combination of 75 % clear float glass on a green float glass base gives the highest lux value at a point 90cm from the opening whereas the lowest value is exhibited through a 25% green float glass with a black float glass base of 75%. The finding shows that glazing with lower Visual Light Transmittance as the base will give a lower Daylight Factor compared to using it on top of the other glazing. Furthermore, although there is a large contrast of Daylight Factor between the 0.9m and 3.6m depth, several combination of glazing achieved the requirement of Malaysian Standard 1525 for daylighting in office

Kurs "Fit für die Facharbeit" kommt gut an

In der Universitaets- und Stadtbibliothek Koeln wird seit 2007 ein Schuelerkurs zur Vermittlung von Informationskompetenz angeboten. Der Kurs "Fit fuer die Facharbeit" soll die SchuelerInnen befaehigen, Literatur zu ihrem Thema zu suchen und Buecher in der USB Koeln auszuleihen. Darueber hinaus soll auch grundsaetzlich Verstaendnis für die vielfältigen Moeglichkeiten im Bereich der Nutzung von Bibliotheken gezeigt werden. Der Artikel beinhaltet eine kurze Beschreibung des Kurses und fasst die Ergebnisse einer Evaluation, die im Sommer 2010 durchgefuehrt wurde, zusammen. Nachdem der Kurs drei Jahre fast unveraendert angeboten wurde und bei den Lehrern positive Resonanz gefunden hatte, stellte sich die Frage, wie die SchuelerInnen selbst den Kurs nach Beendigung ihrer Facharbeit beurteilen. Von den Kursteilnehmern/innen des Zeitraums 2009 - 2010 wurden Fragen zur Zufriedenheit, zum Verstaendnis, zum Bedarf und zum Nutzen des Kurses beantwortet. Die Urteile waren überwiegend positiv. Anregungen und Verbesserungsvorschlaege werden bei der weiteren Konzeption des Kurses beruecksichtigt