Lead Performer: Optimized Thermal Systems — Beltsville, MD
Partners: Heat Transfer Technologies, LLC — Prospect Heights, IL; UTRC — East Hartford, CT
DOE Total Funding: $500,000
Cost Share: $140,000
Project Term: 2016-2019
Funding Type: Building Energy Efficiency Frontiers and Innovations Technologies (BENEFIT) – 2016 (DE-FOA-0001383)

Project Objective

Optimized Thermal Systems, with their partners Heat Transfer Technologies, LLC, and interest from United Technologies Research Center, will develop a manufacturing procedure for a serpentine heat exchanger for heating, ventilation, and air-conditioning systems that has 90% fewer joints than current heat exchangers. Approximately 50-80% of air conditioners and heat pumps are undercharged and leak as much as 10% of their refrigerant annually, which can release greenhouse gases into the atmosphere and reduce system efficiency. Typically the leaks come from joints, which in this system would be reduced by 90% to four inlet/outlet joints. This new set of serpentine tubing has aluminum fins pushed onto a continuous tube that does not need tube expansion.

The performance targets for this technology, as compared to a current state-of-the-art tube-fin heat exchanger:

  • Equal or greater air-side heat transfer coefficient
  • Equal or lower air-side pressure drop
  • Equal or lower heat changer cost
  • Elimination of at least 90% of the joins in a 2-ton residential AC/heat pump system

Project Impact

Heating, ventilation, air-conditioning, and refrigeration systems contribute to greenhouse gas emissions both directly through hydrofluorocarbon refrigerant leakage and indirectly through fossil fuel and electricity consumption. Additionally, reduced refrigerant charge, as caused by leakage, is detrimental to performance and is estimated to be as much as 475 TBTU annually by 2030. This system will minimize refrigerant leakage by eliminating at least 90% of the joints in a 2-ton residential AC/heat pump system, which will increase performance and energy efficiency. 


DOE Technology Manager: Antonio Bouza
Lead Performer: Dr. Reinhard Radermacher, Optimized Thermal Systems

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