APPLICATIONS OF TECHNOLOGY:
- Window and façade framing systems for non-residential building construction
- Yields R5 or better performance for commercial fenestration systems
- Comparable cost to conventional thermal break systems
- Can be integrated into existing manufacturing process
- Manufacturing process allows for color selection flexibility
Berkeley Lab researcher D. Charlie Curcija has developed a thermal break technology that enables aluminum window framing to have equal or better thermal performance than wood or PVC at aluminum’s cost effectiveness and high strength. The thermal break’s unique design, fabricated from traditional or bio-based polymers, results in substantially increased length of thermal break and reduced convection heat transfer while achieving the high strength required for commercial fenestration.
The expected performance improvement of the Berkeley Lab window framing system over the mix of framing options available today is 375%. This yields an overall improvement in a window’s thermal resistance of 75%, assuming the frame represents about 20% of window area. The resulting U-factor (a measure of heat transfer rate) is a 50% improvement over PVC frames and a 100% improvement over wood.
The goal of the new technology is to achieve R5 or better thermal performance. The researchers determined that, with advanced glazing systems, windows incorporating their thermal break system can reach R10 thermal performance while meeting or exceeding the strictest code requirements (AAMA/WDMA/CSA 101/I.S.2/A440 AW ratings).
Commercial builders seek window framing solutions with the cost and strength of aluminum products plus improved thermal efficiency to meet more stringent building codes. Window framing approaches, such as those incorporating poltruded fiberglass and other fiber reinforced polymers, have proven to be prohibitively expensive, and they cannot be integrated into existing manufacturing processes. The Berkeley Lab technology offers a cost effective, structurally sound solution with high thermal efficiency to this construction sector.
DEVELOPMENT STAGE: Proven principle with prototype under construction
STATUS: Issued U. S. Patent 9,828,797. Available for licensing or collaborative research.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
EnergyPlus: Energy Simulation Software for Buildings, CR-2118
REFERENCE NUMBER: IB-3155