Developers of a personal air conditioner designed to reduce energy use in office buildings say they’re on track for commercial release next year. The “μX” micro climate system features a phase change material that solidifies at about 18 degrees C to store cooling generated at night for use during the day.
Dr. H. Ezzat Khalifa
The evolution of the μX: an early design ...
of Syracuse University led the development team, which includes Air Innovations
, Cornell University
, United Technologies Research Center
and Bush Technical LLC
. The team has been working on the system since 2015, funded in large part by a $3.2 million grant
from the U.S. Energy Department’s Advanced Research Projects Agency-Energy. The New York State Energy Research and Development Authority provided $400,000 in follow-on funding in 2016.
Sam Brown, OEM custom director at Air Innovations, is in charge of bringing the product to market. He and Michael Wetzel, president and CEO at Air Innovations, talked about their company’s role in the project.
Q: Describe the μX system size, components and functionality.
Brown: “The current unit is about twice size of a standard PC computer tower. The unit utilizes a phase change material that melts over time. We then run a fan over the material to create an active cooling effect. A compressor then re-solidifies the PCM in the off-peak hours for future on-demand needs.”
Q: Describe the phase change material used in the system: type, melt point, thermal storage capacity, amount used in each unit.
Brown: “Rubitherm, 68F, 8-10 hours, 40 pounds.”
... a version displayed at a recent conference ...
Were different PCMs tested, or did the team focus on one from the start?
Wetzel: “Many PCMs were considered and analyzed before settling on Rubitherm, but no others were tested in operating systems.”
Q: Preliminary tests indicate the prototype can remove more than 32W of heat, surpassing the ARPA-E grant target of 23W. Is the final production model likely to hit that higher number?
Wetzel: “23 watts is the target heat removal directly from a person. Our manikin results showed us exceeding that number in all tests. We tested three different diffuser methods. Some achieved as high as 32 watts removed from the manikin. In all cases we are actually generating more than 500 watt-hours of cooling, enough to cool the airstream 8 degrees F for 10 hours.”
Q: The system is now known as "μX." Will that name be used for the commercial product?
Brown: “No, the commercialized name will more closely reflect the manner in which it's utilized.”
Q: What was the greatest technical hurdle the team faced in developing this product?
Wetzel: “There were many challenges on this project. Part of the program required the development of the world’s smallest scroll compressor. This also means that there was no performance data or design simulation data with which to develop the rest of the system. Our partners on the project had to develop simulation tools based on testing each new component. At Air Innovations our main challenges are designing for manufacturability and the integration and testing of off-the-shelf components as alternatives, as some of the elements of the ARPA-E units are not yet commercially available.”
... and, finally, says Brown, "where we think the unit will potentially go in final production."
What is happening with the project right now? Is it at the pilot stage?
Brown: “Currently, we are working through ARPA-E and New York State Energy grants to fully develop the technology. We are developing the unit for two scenarios. The primary is for 8-10 hours of cooling in any office environment. The other is for four hours to off-load the grid in metropolitan areas with peak power capacity concerns. Several units have been built and tested in controlled environments. We are currently seeking grant opportunities to support larger field trials.”
Q: Can you offer any details on the timeline, projected price, target market and sales projections?
Brown: “Further human testing will be necessary in order to right-size the final product. The unit will likely be ready for market sometime in 2019. The initial price point of the unit will be higher, and then come down based on quantity and market demand, settling around $2,500. It is our goal to bring to market 250-500 units in the first year.
“The exciting opportunity with the μX technology is that it further expands upon our existing Micro Environments product line. The commercialized unit will be able to control the users’ complete environment while not only offering active cooling and heating, but to control their entire surroundings as seen in our other models. Furthermore, our customers will see an ROI with the μX technology by allowing set points in the summer to run higher and temps to run cooler in the winter, reducing building HVAC power needs with a more personal temperature control directly at the desk. We believe this technology can improve worker productivity by allowing individual control, at all times, of their specific environment.”