This literature review provides insights to the use of double skin facades. Double skin facade relates to the somewhat limited comfort range of the human body, and depends on activity and environmental circumstance. It must examine the broad spectrum of human and environmental needs. Fairly, all available materials are assessed in order to arrive at an informed recommendation or decision.
Conceptual Frame Work
Creating a net zero building involves many sustainable systems that have to work together in order to succeed. When I chose to create an exterior façade to save energy, the program “Climate Consultant” recommends that I focus on the following systems to keep my building efficient:
• Day lighting- to help offset the cost of lighting the space.
• Sun Shading- to reduce the need for air conditioning in the summer time.
• Passive Solar Design- to provide a free heating and cooling system by exposing the south facing façade to direct sunlight during the winter months, only allowing the interior of the building to absorb the sunlight while shading the summer sun and not allowing it into the building to keep it cooler inside.
• Cross Ventilation- Directing the wind through the building at certain times of the year will help cool the building without using energy.
• Ceiling Fans- indoor air movement can make it seem cooler.
• Sun/Wind Protected outdoor space- extend internal areas outdoor in cooler weather
• Limit Floor Plan Size- keeping building small will limit amount of energy needed to heat/cool Spaces.
• Plants- along the west façade to shade structure from noon summer sun.
The ultimate goal of the smart exterior façade is reaching zero net energy. The smart exterior façade will promote greater utilization of the facility and greater outreach within the community.
The following series of articles help define what sustainable strategies work best for the exterior façade of a building. These first two articles deal with double-skin façade systems. The systems and ideas they discuss will be the same idea I will cover in the paper. The first article deals with the openness between exterior spaces and interior spaces in buildings. It explains the use of double skin façade. The smart façade unit was installed at the college of architecture building in Georgia institute of technology as a study model. There are three important elements for using the double-skin system: energy use, visual comfort, and thermal comfort. Researchers kept following data for the period of research and finally came up with a conclusion, which can help them to continue their study and use their findings in future projects. In conclusion, the smart façade systems are more advantageous in terms of energy, visual comfort and thermal comfort. The second article compares differences between double-skin façade and single skin façade concerning heating and cooling loads at a number of different locations. In this article, not only they suggest double-skin façades for hot season, but also during cooling season double-skin façade is more cost efficient and energy saving. According to Stelios C. Zerefos, in comparison of double-skin façade with single skin façade, not only the U-value is reduced by 0.23 W/m2 k, but they also reduce their g-values. With this improvement the differences in energy consumption between double-skin façade and a single skin façade is about 42% during office hours in a Mediterranean climate during cooling season.
Technology in Architecture
Technology is transforming our experience of comfort and discomfort in a building. According to the Building Envelopes An Integrated Approach, the comfort range of the human body is slightly limited; it changes with different activities and kinds of environments that they live in. With different environments, human bodies have different responses. According to Jenny Love II, “the environmental conditions directly influenced by building envelope design that relates to comfort are temperature, humidity, light, sound, view, airflow, and air quality”.
The main point that I plan to analyze is creating a double skin façade, which takes fresh air into the interior spaces of modern buildings. Many buildings control their ventilation mechanically. Most of the mechanical ventilation systems in the world are forced-air systems; this air circulation does not use the amount of fresh air that humans’ bodies need in a building. In order to maintain airflow, the system needs to have an understanding of air-change rates and use of fresh air into the interior spaces in a building.
This article details the entire process in selecting materials for smart exterior façade. The paper is interesting in that it gives examples of why we should want to design more sustainable and why we should care about saving energy. The paper listed all kind of glasses that we can use for exterior façade and what are the E-values on different materials for exterior of a building. Designers always want to have a lot of open spaces on their design, which they can use direct sun light and transparency in interior spaces. But, they do not want to use this material and limit themselves in use of materials or change their design. They want to have a control and limit the amount of heat and light that transmitted to the interior spaces. Moreover, explains about the different layers that we can use for the exterior façade to control over the heat.
Finally, is the smart heating and cooling systems that we can use in a building. These systems are improved design methods in a way that designers are able to connect changes on the exterior façade to the mechanical systems inside the building. Understanding of the materials that architects use is the one that explains different Case studies of smart façade system on the exterior of buildings, which act more like human skin, dynamically and responsively, and have reaction to the environmental changes with zero energy. This kind of material can make connection with the smart heating and cooling systems that we use in a building. These systems could automatically turn on or turn off depends on the temperature on the outside of the building or amount of fresh air we need into the interior spaces.