Environment have always directly affected humans. We continuously have kept discovering how to protect ourselves from it, how to learn from it, how to protect it, how to use its natural resources. After all, we mainly pursue how to balance our built society with it. Modern society requires spaces for the grand amount of activities are held daily. And, even though our society’s complexity increments, the environment keep affecting us consistently. One of the consistent environmental effects on humans is our Comfort Zone, mostly affected by thermal aspects, like sun heat impact in tropical and subtropical zones. Then, how have we protected ourselves? What information have we gathered that can helped us act on it? Dr. Pedro A. Muñiz Rivera, a puetorrican architect, explains various themes regarding thermal comfort in tropical climates, using Puerto Rico as case study. In his book, “Enfoque Biotropical para la Arquitectura en Puerto Rico” (Biotropical Approach for Architecture in Puerto Rico) he explains how to achieve thermal comfort in tropical climates using a bioclimatic chart developed by Víctor and Aladar Olgyay. He shows with a diagrammatic chart that to be in comfort zone at tropic, a human has to be in between 70ºF and 82ºF and 20% to 70% of Relative Humidity(HR) [image 1]. He also added that thermal comfort also depends on clothing resistance that might be wearing the human. Nonetheless, Dr. Muñiz’s information can benefit of adding to the research the cultural aspect. It can be a more accurate information if it’s included a research on how influential can be to be culturally accustom or have been exposed to the climate for a considerable amount of time. Dr. Muñiz have also talked about a shading systems. He specialized on vertical, horizontal, mixed, and movable objects as shading technique. [image 2-3] Dr. Muñiz explains that horizontal shading objects are better for north and south façades; vertical for east and west façades; mixed for very hot climates. Although these types of shading objects implementation have worked in many cases, the information might not be updated to today’s technological application to buildings. It can be useful to evaluate how effective are automated and reactive shading systems in order to better maintain thermal comfort in tropical climates without depending on A/C. Another shading system is explained directly by Víctor and Aladar Olgyay in the Princeton University Press. He shows the shading effects of tress and vegetation. Victor and Aladar Olgyay illustrates that trees, if densely planted, can reduce sound, leaves catches the dust and filters the air, helps in visual privacy, and it is also has an excellent thermal performance [image 4]. Personally I completely support the use of vegetation as a shading system to achieve thermal comfort. It might be of use to analyze what trees species are best for thermal comfort purposes, and also to how good they really are by performing measured readings. However, separate objects and vegetation are not the only ways of achieving thermal comfort in the tropic, nor the only way of understanding this system is in buildings as an object. M. Rohinton Emmanuel, on “An Urban Approach to Climate-Sensitive Design, Strategies for the Tropics” explains an interesting concept of sun protection as a part of urban massing. Its called “Shadow Umbrella”. He explains how buildings as part of and urban context can contribute to a group shading system in which their morphology creates shaded public spaces [image 5-7]. He also includes how little attention urban locations in the tropic have put into it. His concept, however, lacks of the counterpart information. It can benefit by adding how density overdose of building’s morphology might reduce psychological comfort zone even when its achieving a thermal comfort. An example can be, New York City, NY. The height and building density in its urbanism protects efficiently sun radiation in summer, but at some spaces it can feel claustrophobic and dark even though having a bright day. Finally, Karla Grijalva, from Arizona State University completed a thesis titled: “Associative Design for Building Envelopes; Sun Control and Shading Devices”. She explains the importance of using shading systems for the better performance of Energy Use on Buildings. She expresses that openings on a building's envelope can contribute to solar heat gain if openings are not well protected nor have a high performance glazing for reducing solar heat gain [image 8]. Ms. Grijalva also includes that solar control in buildings not only helps on energy balance, it also helps on reducing power use. Ms Grijalva’s expressions are accurate regarding the need for sun protection in tropical climates in order to be responsible on energy consumption. It might have help her tesis to include what might be a negative aspect on using complete shading systems in tropics, regarding material, methods or technologies. It’s clear how complex can be to achieve thermal comfort in a tropical climate. Personally is a balance game that can be achieve with simple natural aspects and decisions. Vernacular architecture have taught us a lot on it. But testing today’s century method is never a bad idea for growth.
SOURCES: • Muñiz, Pedro. Enfoque Biotropical para la Arquitectura en Puerto Rico. San Juan, Puerto Rico, Dr. Pedro Muñiz, 2011
• Rohinton, Emmanuel. An Urban Approach to Climate-Sensitive Design, Strategies for the Tropics. Abingdon, Oxon & New York,NY, 2005
• Olgyay, Aladar and Victor. Solar Control & Shading Devices. Princeton, New Jersey, 1957 • Grijalva, Karla. Associative Design for Building Envelopes. Sun Control and Shading Devices. Arizona State University, Arizona, USA, 2012