Heat exchanger system and method of operation

A method of operating a heat exchanger, comprising

• rejecting heat from a gas comprising water vapor on a heat rejection side fluid flow path to a heat absorption side of the heat exchanger to form liquid droplets of condensed water at a first surface energy level on a hydrophobic surface of the heat exchanger on the heat rejection side fluid flow path that is in thermal communication with the heat absorption side of the heat exchanger;
• applying an electric field to the hydrophobic surface to reduce a contact angle between the individual droplet surfaces and the hydrophobic surface and increase droplet surface energy to a second surface energy level;
• and
• removing the electric field to increase the contact angle between the individual droplet surfaces and the hydrophobic surface, and reduce droplet surface energy to a third surface energy level greater than the first surface energy level and greater than a surface energy level for a free droplet, converting a portion of the droplet surface energy to kinetic energy to detach droplets from the hydrophobic surface;
• and
• removing detached droplets from the heat rejection side fluid flow path.