Here’s a clever idea. A group of scientists, from the University of California, San Diego, is in the process of developing a smart fabric, of sorts, that could keep the wearer’s body within a comfortable temperature range, irrespective of how hot or cold it really is. Aimed at reducing the need for separate building-level air conditioning systems, and the associated carbon dioxide emissions, the research is part of a three-year project called ATTACH, i.e. Adaptive Textiles Technology with Active Cooling and Heating.
Today, heating and air conditioning systems are an indispensable part of the American household, amounting to around 16-percent of a family’s annual electricity bill. According to a recent study, by the U.S. Department of Energy, up to 5-percent of the country’s total electricity is used by air conditioners. Consuming more energy for A/C than the rest of the world combined, the United States is currently spending billions of dollars to generate the electricity needed for the purpose. More alarming, indeed, is the fact that air conditioning results in the emission of nearly 100 million tons of carbon dioxide into the atmosphere, each year, in the U.S. alone. This averages at about two tons of CO2, from each household.
Recent surveys have shown that the use of home and office air conditioners has had a drastic increase in developing countries, especially China and India. For instance, a study, by the International Energy Agency, states that the sales of air conditioning systems has nearly doubled, in China, over the last five years. Despite the prevailing power shortages, with over 400 million people having no access to electricity, India too has shown a marked increase in sales of air conditioners. Given the current trend, scientists believe that the number of households with A/C would rise from today’s 13-percent to a staggering 70-percent, at the turn of the century.
While efforts are being made to develop energy-efficient air conditioners and build greener, and more eco-friendly homes, the best plan of action is to learn to live without the luxury of artificial air conditioning. Led by renowned professor of Nano-engineering, Joseph Wang, the team at UCSD is working to reduce dependency on HVAC (heating, ventilating and air conditioning) systems. According to Wang, controlling the temperature around the wearer’s body, as opposed to that of an entire room, could help decrease a building’s energy consumption by an impressive 15-percent. Speaking about the research, Wang said:
In cases where there are only one or two people in a large room, it’s not cost-effective to heat or cool the entire room. If you can do it locally, like you can in a car by heating just the car seat instead of the entire car, then you can save a lot of energy. Regardless if the surrounding temperature increases or decreases, the user will still feel the same without having to adjust the thermostat.
Unlike other related fabric technologies that focus mainly on outdoor use, ATTACH is intended for use inside one’s home or office, at a temperature range of 19°C to 26°C. The highly-sensitive smart textile regulates the individual’s body temperature – keeping it at a comfy 93° F – in response to changes in the ambient temperature. This is achieved by means of special polymers, present inside the ATTACH, that are capable of altering the fabric’s insulation level (i.e. thickness and porosity) in accordance with the prevailing temperature. For instance, it will automatically become thicker when the room gets colder, and vice-versa.
In addition to the polymers, the wearable air conditioner will also include a set of supplementary heating and cooling systems, known as thermoelectrics, designed to regulate the temperature of certain “hot spots”, like the underside of our feet and our back, that usually get hotter than the rest of our body. Furthermore, they need to be printable, in order to be seamlessly incorporated into the fabric. A professor of mechanical engineering at UC San Diego, Renkun Chen, and his team, is currently developing these tiny, wearable contraptions. He said:
This is like a personalized air-conditioner and heater… With the smart fabric, you won’t need to heat the room as much in the winter, and you won’t need to cool the room down as much in the summer. That means less energy is consumed. Plus, you will still feel comfortable within a wider temperature range.
Interestingly, ATTACH will also be self-powered, with the help of rechargeable batteries and specially-engineered biofuel cells that use human sweat to generate usable energy. According to the team, these parts need to be ultra-thin and flexible, in order to be printed directly onto the fabric. Wang said:
We are aiming to make the smart clothing look and feel as much like the clothes that people regularly wear. It will be washable, stretchable, bendable and lightweight. We also hope to make it look attractive and fashionable to wear.
The project is being funded by a $2.6 million grant from the Advanced Research Projects Agency – Energy (ARPA-E).