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H2O + C = cool idea

Forty years ago the protagonist in "The Graduate" was told the magic word for the future was "plastics." I would suggest the magic word for our future now is "water.
Written by Harry Fuller, Contributor

Forty years ago the protagonist in "The Graduate" was told the magic word for the future was "plastics." I would suggest the magic word for our future now is "water." Two Michigan innovators just won a prize for an air conditioning system that uses water as the coolant and carbon in the compression turbine. John Barrie and Dr. Norbert Müller recently won an award for coming up with the best plan to cut energy use in air conditioning systems. The goal: reduce energy use in home and small businesses during the air conditioning season. In places like Dubai that can be year round.

I had a chance to talk with Barrie by phone. He lives in Ann Arbor and Müller lives just up the road in East Lansing, MI. Muller's on the Mechanical Enginering faculty there at Michigan State. Barrie runs a non-profit and designs low cost environmental solutions for the poorer parts of the globe.

Using water as an air conditioning coolant is not new, Barrie explained. Some large systems in Europe and Japan use it already. Here's a five-year-old engineering abstract from Japan: it describes a water-coolant system. The catch in the past has been the need for expensive, high-speed turbines on the compression side to make the water a viable coolant.


Here's my understanding of Barrie's description of how their innovative air conditioning system would work: This is not a swamp cooler. It's a "standard" air conditioning system that pumps out cool air, using water vapor as the refrigerant. That's far more efficient than the other chemicals now used in home and small business systems in the U.S (mostly R134A). To make water work you need a much faster revolving compression system than current air conditioners.

Click to see full image. The inside of carbon fiber compressor wheel. Courtesy Barrie and Muller.

Barrie and Müller solved this problem with a carbon fiber turbine. The fibers are all aligned with the stressing forces, giving the tubine both the strength and minimal weight that provides high compression and energy efficiency. Current large scale air con systems using water as a coolant depend on pricey titanium turbines. Those soft little home-sized aluminum blades just wouldn't take the stress.

Further Dr. Muller has devised a thin shell motor that is both efficient and quiet to run the turbine. The energy input is electricity but this water/carbon air con system would be cheaper to build than current systems and be 30% more energy efficient. As Barrie said, "You have to be both better and cheaper to overtake an existing technology." If this air conditioner gets into production the energy savings could be significant. Barrie says about half of American homes run air conditioning all summer long, non-stop. Due to lower power needs the new air con technology could help reduce generating plant emissions including mercury and greenhouse gases.

Here's Barrie's blog on inexpensive, environmental-friendly design.


At his non-profit Barrie works on practical designs "for the other 90%." Those are the people living on less than $2US per day. He was proud of one of their recent achievements: they've designed an inexpensive solar-powered freezer for Africa where food spoilage is a huge resource sump. Barrie went on to praise the collective wisdom of designers connected by the Internet. He uses his own blog site to garner collaboration. The point is to solve real-life design problems. No meetings, no conferences, no expensive air fares. One recent project included Barrie and two collaborators he never met: one in Israel, another in Pakistan.

Barrie's a big fan of online social networking for examining and solving design and engineering problems. It is no wonder he and Müller plugged into the air conditioning contest publicized at Innocentive. http://www.innocentive.com/ The 7-year-old site proclaims: "We believe in the power of open innovation, bringing together creative minds to create breakthrough solutions that touch every human life."

The future of air con design from Barrie and Müller? They retain the intellectual rights and are talking to both VC and traditional air con makers. Stay tuned.

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