DePneumatic Facades

The Potential Advantages of Deflated Envelopes

Overview

Authors


Abstract

DePneumatic Facades: this research project is intent on expanding upon known pneumatic building envelope systems, evolving pneumatic systems to use it as a vacuum system rather than an air filled system. With over 47% of the U.S. Energy used each year attributed to buildings, and a large portion of that energy loss due to building envelopes themselves, the need to develop a new building envelope that is energy efficient, lightweight, a good candidate for retrofit, and potentially a major insulator, is a clear objective. Pneumatic air-supported structures that are supported by internal air pressure are perhaps the most cost-effective, and lightweight type of enclosure for very long spans, and have been a popular form of construction since the 1970’s. The variant of this research, De-Pneumatics, will be using the same principle as pneumatics, but in reverse - creating air tight building envelope systems (between two membranes) that are based on a vacuum, or near vacuum, instead of air pressure; with this system the vacuum will create a highly insulated wall, one that will eliminate the two most problematic issues of normal pneumatic systems – insulation value and sound transparency. Recently vacuum envelope systems have been developed, but have been limited to vacuum insulated panels for refrigerators and vacuum envelopes for experimental bridges; but overall research has been very limited in the topic of using vacuums for a building envelope system. This ongoing scholarly research has covered research of other precedents in vacuum envelope systems, worked alongside membrane envelope companies including Vector Foiltec, developed 2D and 3D design models, developed small scale prototypes, proof-of-concept mock ups, coordinated with structural and sustainable engineers for analysis of the designs, and created presentation drawings and renderings of the completed design proposals.

Introduction

According to the Architecture 2030 group, buildings are responsible for 47.6% of the total energy use in the United States, with over half of that contributed to energy loss (or

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Background

Pneumatic Structures and/or Inflatable structures, are typically membrane structures supported by the pressure of compressed air (air-supported structures), often with a network of cables to stiffen the fabric and a

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Method

The project consisted of developing small prototype shading systems digitally that would hypothetically be attached to an existing building, which were then enclosed with prototypes of the depneumatic system. The

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Testing

The Digital models had analysis attached to each configuration, including descriptions of the physical geometries, panel configurations, heat transfer, calculations of how much physical material is touching the inside and

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Data

Data was collected from the experiments in the summer of 2019.

The pressure generated from each experiment equated to .2-.3 bars.

Industrial Vacuum

Power: 6 horsepower à 3300 ft-lbs

Velocity: 150 cfm à 2.

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Explanation

Analysis of modeling and desktop physical modeling will be presented at a later date. With the DePneumatic Systems a number of issues are potential problems to control and overcome; quality

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Conclusion and Future Work

Aesthetics: The aesthetic qualities of a DePneumatic System will likely be a challenging and interesting to explore, as the geometries generated from suction based systems are not a typical typology

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Acknowledgements

USC Undergraduate Research Associates Program, Office of Undergraduate Programs

USC Undergraduate Research Assistants Abrianna Aiken, and Carol Ann Lucas