Sorry, you need to enable JavaScript to visit this website.

Building Efficiency

University of Maryland

Thermoelastic Cooling

The University of Maryland (UMD) is developing an energy-efficient cooling system that eliminates the need for synthetic refrigerants that harm the environment. More than 90% of the cooling and refrigeration systems in the U.S. today use vapor compression systems which rely on liquid to vapor phase transformation of synthetic refrigerants to absorb or release heat. Thermoelastic cooling systems, however, use a solid-state material--an elastic shape memory metal alloy--as a refrigerant and a solid to solid phase transformation to absorb or release heat. UMD is developing and testing shape memory alloys and a cooling device that alternately absorbs or creates heat in much the same way as a vapor compression system, but with significantly less energy and a smaller operational footprint.

University of Maryland

Meta-Cooling Textile with Synergetic Infrared Radiation and Air Convection for Bidirectional Thermoregulation

Led by Dr. YuHuang Wang, the "Meta Cooling Textile (MCT)" project team at the University of Maryland (UMD) is developing a thermally responsive clothing fabric that extends the skin's thermoregulation ability to maintain comfort in hotter or cooler office settings. Commercial wearable localized thermal management systems are bulky, heavy, and costly. MCT marks a potentially disruptive departure from current technologies by providing clothing with active control over the primary channels for energy exchange between the body and the environment. In hotter surroundings, the fabric's pores open up to increase ventilation while changes in the microstructure of the fabric increase the amount of energy transmitted through the fabric from the wearer. In cooler conditions, these effects are reversed to increase the garment's ability to insulate the wearer. The added bidirectional regulation capacity will enable the wearer to expand their thermal comfort range and thus relax the temperature settings in building.

University of Maryland

Robotic Personal Conditioning Device

The University of Maryland (UMD) will develop a robotic personal attendant providing improved comfort levels for individuals in inadequately heated/cooled environments. This mobile robotic platform will be fitted with a small, battery-powered, high-efficiency vapor compression heat pump and will be highly portable and able to follow an assigned person around during the course of the day, providing localized heating and/or cooling as needed while reducing the energy required to heat and cool buildings.

University of Notre Dame

Compact, Efficient Air Conditioning with Ionic Liquid-Based Refrigerants

The University of Notre Dame is developing an air-conditioning system with a new ionic liquid and CO2 as the working fluid. Synthetic refrigerants used in air conditioning and refrigeration systems are potent GHGs and can trap 1,000 times more heat in the atmosphere than CO2 alone--making CO2 an attractive alternative for synthetic refrigerants in cooling systems. However, operating cooling systems with pure CO2 requires prohibitively high pressures and expensive hardware. Notre Dame is creating a new fluid made of CO2 and ionic liquid that enables the use of CO2 at low pressures and requires minimal changes to existing hardware and production lines. This new fluid also produces no harmful emissions and can improve the efficiency of air conditioning systems--enabling new use of CO2 as a refrigerant in cooling systems.

University of Texas, Austin

Low-Cost Solution Processed Universal Smart Window Coatings

The University of Texas at Austin (UT Austin) is developing low-cost coatings that control how light enters buildings through windows. By individually blocking infrared and visible components of sunlight, UT Austin's design would allow building occupants to better control the amount of heat and the brightness of light that enters the structure, saving heating, cooling, and lighting costs. These coatings can be applied to windows using inexpensive techniques similar to spray-painting a car to keep the cost per window low. Windows incorporating these coatings and a simple control system have the potential to dramatically enhance energy efficiency and reduce energy consumption throughout the commercial and residential building sectors, while making building occupants more comfortable.

University of Wisconsin

WBG-Enabled Current-Source Inverters for Integrated PM Machine Drives

The University of Wisconsin-Madison (UW-Madison) and its project team will develop new integrated motor drives (IMDs) using current-source inverters (CSIs). Recent advances in both silicon carbide (SiC) and gallium nitride (GaN) wide-bandgap semiconductor devices make these power switches well-suited for the selected CSI topology that the team plans to integrate into high-efficiency electric motors with spinning permanent magnets. The objective is to take advantage of the special performance characteristics of the technology to increase the penetration of variable-speed drives into heating, ventilating, and air conditioning (HVAC) applications. Many of the HVAC installations in the U.S. residential and commercial sectors still use constant-speed motors even though there is a well-recognized potential for major energy savings available by converting them to variable-speed operation. If successful, the new IMDs will be capable of producing significant energy savings in a wide variety of industrial, commercial, and residential applications ranging from air conditioners to pumps and compressors.

Virginia Commonwealth University

Fabrication of Inexpensive Aerogel Panes for Window Retrofit

Virginia Commonwealth University (VCU) will develop innovative methods to produce aerogel-on-glass windowpanes for window retrofits. Silica aerogels are porous materials that can be used to control heat transfer across windows. However, widespread use of silica aerogels in windows has been limited by their mechanical fragility, difficulties with transparency, and high manufacturing costs. The team will use newly developed cross-linked aerogels that significantly improve the mechanical strength and durability of aerogels. Aerogels are typically produced through either air drying or supercritical drying. Air drying is inexpensive, but induces stresses that can lead to fragmentation. Supercritical drying is superior, but is expensive. VCU will employ an alternative drying method, freeze drying, in which the material is frozen and ice is sublimated off. VCU estimates that aerogel production using freeze drying can cut production costs by about 40% compared to supercritical drying. VCU's aerogel material would be placed between a glass pane and polycarbonate films to produce an effective windowpane for single-pane window retrofits.

ARPA-E brings together experts from diverse disciplines and industries to frame new ways of looking at the energy challenge. By viewing the problem through a different lens, ARPA-E brings together new capabilities to develop new technology solutions. The DELTA and MONITOR programs illustrate this novel approach well. In this video, Associate Director of Technology Dr. Patrick McGrath discusses how ARPA-E has reframed the challenge of building efficiency with the DELTA program and methane leaks with the MONITOR program differently in order to yield “out of left field” technologies that can lead to transformational gains. The video features two projects – University of California San Diego’s DELTA project and Rebellion Photonics’ MONITOR project.

ARPA-E is supporting some of the best and brightest scientific minds across the country to turn aspirational ideas into tangible technology options. By presenting an ambitious energy challenge to the U.S. research and development community, ARPA-E attracts ideas from a diverse group of innovators, representing traditional and non-traditional energy backgrounds, who look to address energy challenges in new and exciting ways. Founder and CEO of Alveo Energy Dr. Colin Wessels and Co-Founder and CEO of Indoor Reality Dr. Avideh Zakhor are two ARPA-E project investigators that have made great progress, with support from the ARPA-E Tech-to-Market team, in advancing their technologies out of the lab and into the marketplace.

ARPA-E helps to translate cutting-edge inventions into technological innovations that could change how we use, generate and store energy. In just seven years, ARPA-E technologies are demonstrating technical and commercial progress, surpassing $1.25 billion in private sector follow on funding. In this video, ARPA-E Director Dr. Ellen D. Williams highlights an exciting project from Stanford University that is developing a radiative cooling technology that could enable buildings, power plants, solar cells and even clothing to cool without using electric power or loss of water. This project is just one example among ARPA-E’s 400+ innovative technologies that are reimagining energy and helping to create a more secure, affordable and sustainable American energy future.


Subscribe to Building Efficiency