Vacuum Glass for R-10 Windows

The one remaining barrier to achieving a marketable R-10 window is the inherently-high manufacturing cost of oven-sealed vacuum glass. High cost is inherent in the use of solderglass seals, which require a heating-cooling cycle requiring hours. In contrast, one dual pane unit can be sealed every 30 seconds. The manufacturing cost for oven-based vacuum glass is over four times that of dual pane insulating glass. To compete with dual pane, next-generation vacuum glass seal material will abandon solderglass and brazing paste for aluminum foil, cold-welded directly to glass in only a fraction of a second. To complement this, vacuum glass production will abandon thermal degassing with a combination of room-temperature processes, including plasma degassing, and the use of a getter that can finish the evacuation process after seal-off and preserve life for 50 years. Collaboration with the Edison Welding Institute ruled out practical use of an ultrasonic bar welder to obtain speed. In response, the research effort pivoted to building a new and larger seam welder which increased weld speed by a factor of 3. A Cost Rollup Model confirmed this is sufficient to achieve cost parity with dual pane. Collaboration with the University of Sydney revealed the root cause of microleakage, unexpectedly leading to a breakthrough in sonotrode geometry capable of making hermetic welds. The University also reconfirmed that the novel whisker standoff developed by V-Glass can deliver R10-capable vacuum glass. The proposed project will reduce barriers to private investment, primarily by improving welding reliability and yield, developing an oven-free degassing strategy, and scaling up these manufacturing processes to a pilot line capable of producing glazing of area larger by a factor of 9. Warranty risk will be reduced by conducting accelerated life testing on glazing samples produced by the pilot line, further de-risking the investment decision. A successful project will provide private investors the confidence they require to build the first commercial R10-capable VIG line as soon as 2023, consistent with the goal of the DOE windows roadmap. Widespread use of R-10 windows can reduce total US energy use (and greenhouse gas emissions) by 1% by 2030, and help position the US at the forefront in a global market totaling $40 billion per year.