EFRI-SEED: Living Wall Materials and Systems for Automatic Building Thermo-Regulation

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

The objective of this EFRI-SEED project is to study a "living wall" concept that acquires its original idea from biomimicry of the body's thermo-regulation systems (i.e., respiratory and circulatory systems) that can efficiently adapt to changes in the surrounding environment via sophisticated heat transfer processes and metabolic adjustments. The novel living wall system embeds two sets of optimized microvascular fluid channel (MVFC) networks and a distributed phase change medium (PCM) into an innovative polymer-based wall unit to allow autonomous movement of air and liquid and charge/discharge of PCM in response to real-time indoor and outdoor temperature variations so as to dynamically regulate the thermal behavior of the building envelope and the entire dwelling. While natural convection drives air through a porous holding material, novel hydrogels with tailored temperature sensitivity will be developed to move liquid in the wall thickness direction. By combining hydrogels with different temperature sensitivities the responsiveness will be increased and the amount of free liquid reduced to negligible level. Mathematical models and computational design approaches will be developed to optimize the layout of the holding material, the MVFCs and PCM components. A prototype of the living wall will be fabricated and studied under a series of thermal and structural loading scenarios. The performance of the entire living wall system under dynamic indoor and outdoor conditions will be systematically investigated through multi-physics simulations and novel design approaches to seamlessly integrate the living wall concept into current and future building constructions. This project will expedite the research for net-zero-energy buildings with significant reduction of heating and cooling energy needs via smart building envelope designs. Based on preliminary results, the new living wall concept is expected to reduce 80-95% of the current building energy needs for offsetting adverse heat losses/gains through conventional walls and for providing extra ventilation and electrical lighting due to tighter and opaque wall structures. The success of this research will greatly stimulate the application of biomimetic design principles for developing sustainable energy efficient engineering designs and reshape the current building design and construction philosophy and practice. The proposed research will ultimately lead to the development of a brand new interdisciplinary academic program in Bio-Architectural Science and Engineering (BASE). This will include the development of a horizontally and vertically integrated cross-disciplinary research and education program for pre-college, undergraduate and graduate students from broad fields of interest, as well as developing a rich, multi-faceted outreach program. The PIs will team up with the NSF-funded Colorado Alliance for Graduate Education and the Professoriate and College of Engineering's BOLD Center to attract and integrate undergraduate and graduate students from underrepresented groups into this research project. A formal assessment plan will be implemented to measure the success of the education and outreach activities. The FY 2010 EFRI-SEED Topic that supports this project was sponsored by the US National Science Foundation (NSF) Directorates for Engineering (ENG), Mathematical and Physical Sciences (MPS) and Social, Behavioral and Economic Sciences (SBE), and Computer & Information Science and Engineering in collaboration with the US Department of Energy (DOE) and the US Environmental Protection Agency (EPA).