Synapse Helps NREL Create More Efficient Air Conditioner Design

Source:  Synapse Product Development, Press Release, August 2, 2010.  Synapse Product Development is working with the US Department of Energy’s National Renewable Energy Laboratory (NREL) to engineer prototypes for a desiccant* enhanced evaporative air conditioning (DEvap A/C) system.

Each year, air conditioning uses approximately 4 out of 41 quadrillion Btu (quads) of the source energy used for electricity production in the United States alone, which results in the release of about 235 million metric tons of carbon dioxide into the atmosphere†.  The new NREL concept uses desiccant materials which remove moisture from the air by using heat and advanced evaporative technologies. This results in a cooling unit that uses 90% less electricity and up to 80% less total energy than traditional air conditioning.

“Air conditioning technology as we know it today was invented over 100 years ago by Willis Carrier. Improving comfort and efficiency of this century-old-technology is nearing its end. NREL’s DEvap A/C system may be the next leap needed to address our nation’s ever expanding requirements for efficiency and healthy living. NREL has partnered with Synapse Product Development to take the design from the laboratory to a full scale prototype, which is a critical step in creating a viable product,” Eric Kozubal, a Senior Engineer at NREL said. “Synapse’s team has been instrumental in scaling up the DEvap A/C design.”

NREL, the only federal laboratory dedicated to the research, development, commercialization and deployment of renewable energy and energy efficiency technologies, selected Synapse to develop functional 1/10th and full scale proof of concept prototypes to demonstrate physically what theoretical modeling and simulations of the DEvap A/C technology have shown. The full scale prototypes will be demonstrated to potential commercial partners for real world application.

“While in principle, the processes involved in the DEvap A/C system are quite simple—desiccation of air and evaporative cooling—the challenge has been integrating everything into a compact and elegant design,” said Ian Graves, Synapse Mechanical Engineer. “In order to achieve the high efficiency that NREL has modeled, you need to have a lot of air in intimate contact with desiccant and water. Having air, desiccant and water flowing in different directions in such a small space has required some very clever design work by Synapse’s
engineering team.”

Along with reduced energy usage, the DEvap A/C technology improves air comfort and quality with independently managed temperature and humidity control.  This mitigates problems traditional air-conditioning units have such as mold, reduces electrical peak load demand which translates to less strain on the electrical grid, and decreases greenhouse gasses by eliminating chlorofluorocarbons in the design.

“A successful design would be the equivalent of a major automotive company rolling out a new car that could achieve several hundred miles to the gallon,” Redwood Stephens, Director of Mechanical Engineering, said describing the innovation required for the DEvap system.

* Desiccants are an example of a thermally activated technology (TAT) that relies on heat instead of electricity. Desiccant materials absorb water from the air and are then dried by thermal heat. Many thermal sources, such as natural gas, combined heat and power systems, and renewable energy, can be used to dry desiccants. [NREL 2010 – NREL/FS-6A4-47566]

†DOE. 2009. Buildings Energy Data Book.

Current Estimate by NREL, 235 MMT: {4 Quads * 58.73 MMT/Quad = 235 MMT CO2}