Bi-directional Porous Media Phase Change Heat Exchanger


This technology is applicable to systems where heat needs to be transferred in two directions, such as charging/discharging a thermo-adsorptive battery or interior climate control.

Problem Addressed

Traditional heat exchangers only transfer heat in one direction.  This technology allows a porous media evaporator to also act as a condenser to enable heat transfer in both directions.  Additionally, the operation life of the porous media is extended by making it permanently hydrophilic.


This heat exchanger uses evaporation to transfer heat in one direction and drop-wise condensation to transfer heat in the other direction.  In evaporation mode, liquid supplied to minichannels under a copper porous media move into the media due to capillary forces.  Inside the media, the liquid evaporates, removing thermal energy.  In condensation mode, liquid condenses on the top surface of the porous media to transfer heat into the media.  If higher condensation performance is required, a hydrophobic, nonporous region can be added adjacent to the porous media. 

The copper porous media must remain hydrophilic to ensure proper function in evaporation mode.  However, contaminants during normal operation can quickly render copper surfaces hydrophobic and stop evaporation.  This technology solves that problem by growing CuO/Cu2O nanostructures throughout the media, which makes the media permanently hydrophilic, even in the presence of contaminants.


  • Bi-directional heat transfer
  • Large heat flux using evaporation and condensation
  • Permanently hydrophilic copper porous structure

Intellectual Property

IP Type: Granted US Patent

IP Title: Bi-directional porous media phase change heat exchanger 

IP Number: 10,739,089

Related Technologies

This technology is part of a portfolio on thermal management and recovery, along with Technology 15230-16953.