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Non-metallic Heat Exchangers (CABLE)


c.       Non-metallic Heat Exchangers (CABLE)

This subtopic solicits proposals for next-generation non-metallic heat exchanger systems to improve the energy efficiency of heat pumps and air conditioners over a broad range of operating conditions for building and industrial applications that leverage CABLE non-metallic materials with enhanced thermal conductivity.


Current state-of-the art, air-to-refrigerant heat exchangers typically use copper-tube, aluminum-fin construction, with internal enhancement in the tubes and lances or louvers in the fins to promote heat transfer. Metal derived heat exchanger designs are today’s state-of-the art (SOA) heat exchangers, like microchannel heat exchangers (MCHX).

Prior R&D investment by DOE have looked at, high performance compact heat exchanger, low charge heat exchanger designs and rotating designs. The development of polymer or non-metal heat exchange designs are ideal due to their light weight, manufacturing potential, wide range of geometric design possibilities, corrosion resistance, and potential to be low cost. Polymer heat exchangers have not taken off as a practicable solution due to their relatively low thermal conductivity.


Considering the potential advantages non-metallic enhanced conductivity materials afford, this subtopic seeks new designs for heat exchangers suitable for condensers or evaporators in air conditioners or heating-only heat pumps, as well as heat exchangers suitable for both condensing and evaporating for reversible heat pumps. All solutions must have the potential to enable the market acceptance at scale.


Given the wide range of technology suitable for this subtopic, specific application targets are not defined but proposed innovations must exceed the state-of-the-art performance significantly. Applications must demonstrate progress in Phase I and achievement in Phase II of the following performance and cost targets:

Non-metallic Heat Exchangers



Performance, heat transfer rate (UA)

> 500% compared to state-of-the-art designs

Physical size

> 50% reduction compared to state-of-the-art designs

Fan, blower, or pump parasitic energy consumption

> 30% reduction compared to state-of-the-art designs

Required cleaning intervals, or difficulty of cleaning, to maintain as-new performance

Little to no increase as compared to state-of-the-art designs

Susceptibility to damage or corrosion or performance degradation during manufacture, assembly, transportation, installation, or use

Little to no increase as compared to state-of-the-art designs for relevant applications

Defrost requirements (for applications such as outdoor air-to-refrigerant heat exchangers)

Little to no increase as compared to state-of-the-art designs

Material Cost

> 40% lower cost compared to Aluminum design, lowest-cost material/designs


Please refer to Topic 12 (BTO) for other opportunities related to Building technologies.

Questions – Contact: Fredericka Brown, Building Technologies Office,


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