Experimental Studies of a Passive Cooling Roof in Hot Arid Areas

One of the most significant current discussions in the built environment, architectural practice, theory, and procedures is “Passive Design”. It is becoming very difficult to ignore the issues of passive architectural design strategies in buildings. Recent studies emphasized the need for passive architectural design strategies and the application of the courtyard as a passive design strategy for cooling in buildings. Also, that the courtyard is very suitable in almost all building typologies in all the climatic zones due to its passive tendencies for cooling. Its cooling potentials can be achieved only when design requirements are not ignored. The courtyard has social, cultural, religious, and environmental benefits. Despite its abundant advantages, research effort towards courtyard design requirements is very scarce. Therefore, the main objective of this study is to investigate the design of central courtyard as a passive cooling strategy for improving indoor thermal comfort in Universiti Teknologi Malaysia (UTM) Buildings. Courtyard design requirement such as the courtyard configurations, orientation, and natural features in courtyard buildings in UTM were investigated. Besides the design variants, courtyard usage in such buildings was also examined. The methodology of this study involved the developing of a checklist based on literature for the field survey. Forty-six (46) courtyards in thirty-two (32) buildings in UTM were surveyed, and the statistical description method was used to interpret and analyzed the data. The Results of this quantitative study shows that UTM central courtyards buildings were designed based on a cautious consideration to orientation and configurations to enhance their effective passive cooling potentials, however, only two courtyards had water pools. The study concluded that courtyards in UTM buildings are creatively designed but future experimental studies to appraise their thermal performances is required, and future simulation studies can predict a better design requirement for optimum performance. Therefore, further simulation studies are recommended.

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CHALLENGES OF PASSIVE COOLING TECHNIQUES IN BUILDINGS: A CRITICAL REVIEW FOR IDENTIFYING THE RESILIENT TECHNIQUE

Jurnal Teknologi ◽

10.11113/jt.v78.5748 ◽

2016 ◽

Vol 78 (6) ◽

Author(s):

Abbas M. Hassan ◽

Hyowon Lee ◽

Segyu Oh

Keyword(s):

Critical Review ◽

Passive Cooling ◽

Arid Areas ◽

Existing Buildings ◽

Passive Technique ◽

New Buildings ◽

Cooling Technique

Although many studies have investigated the potential of passive cooling technologies in hot and arid areas, an important question remains. Why did architects ignore the passive cooling technologies in new buildings despite their sustainability? This study is based on this pivotal question. This study aims to review and explore the impediments that undermine the use of these technologies in hot, arid areas; moreover it intends to determine the most resilient passive cooling technique which may be used as a master technique in buildings by architects. The study focuses on twelve of a proposed passive technologies. These techniques are reviewed according to their potentials and challenges. Hence, the drawbacks of each passive technique will be identified in order to recognize the most resilient passive technology. This study suggests that spatial limitations are the most salient challenges facing architects when they attempt to utilize passive cooling technologies. This study also concludes that the openings created in the upper parts of external walls is the most flexible technique that can be implemented in new and existing buildings, without any of the aforementioned impediments.

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Studies on solar passive cooling techniques for arid areas

Energy Conversion and Management ◽

10.1016/s0196-8904(98)00039-9 ◽

1999 ◽

Vol 40 (1) ◽

pp. 89-95 ◽

Cited By ~ 49

Author(s):

N.M. Nahar ◽

P. Sharma ◽

M.M. Purohit

Keyword(s):

Passive Cooling ◽

Arid Areas

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3-D reconstruction and analysis of mammalian mitotic spindle structure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123295 ◽

1992 ◽

Vol 50 (1) ◽

pp. 578-579

Author(s):

Kent McDonald ◽

David Mastronarde ◽

Rubai Ding ◽

Eileen O'Toole ◽

J. Richard McIntosh

Keyword(s):

Cross Sections ◽

Mitotic Spindle ◽

Experimental Studies ◽

Video Camera ◽

Three Dimensions ◽

Mitotic Spindles ◽

Black And White ◽

Reconstruction Methods ◽

Spindle Structure ◽

Tissue Culture Line

Mammalian spindles are generally large and may contain over a thousand microtubules (MTs). For this reason they are difficult to reconstruct in three dimensions and many researchers have chosen to study the smaller and simpler spindles of lower eukaryotes. Nevertheless, the mammalian spindle is used for many experimental studies and it would be useful to know its detailed structure.We have been using serial cross sections and computer reconstruction methods to analyze MT distributions in mitotic spindles of PtK cells, a mammalian tissue culture line. Images from EM negatives are digtized on a light box by a Dage MTI video camera containing a black and white Saticon tube. The signal is digitized by a Parallax 1280 graphics device in a MicroVax III computer. Microtubules are digitized at a magnification such that each is 10-12 pixels in diameter.

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