Advanced Heat Exchanger Coatings to Improve Energy Efficiency of Industrial Refrigeration System

Nelumbo Inc.


Hayward, CA

Recipient Location


Senate District


Assembly District



Amount Spent



Project Status

Project Update

The project team has produced the first coated 2 refrigerant ton coil for 3rd party performance testing.

The Issue

Industrial refrigeration systems rely on refrigerant-to-air heat exchangers to create temperature-controlled space. Ice continually forms on evaporator coils because their surface is below the freezing point of water and moisture from the air will condense, freeze, and form frost. Frost formation diminishes the ability of the coil to cool the air by acting as a thermal barrier and blocking the flow of air. Overtime frost diminishes system efficiency and leads to inadequate cooling and system failure which necessitates the need to defrost. Defrost is an energy intensive process which accounts for up to 21% of the energy consumption of refrigerated systems through direct consumption of energy.

Project Innovation

Nelumbo, Inc. has developed surface modified coated evaporator coils to address the inefficiencies from frost formation and the need to defrost. To date there are no anti-ice coating products available for industrial heat exchangers. . The surface modification will utilize an innovative advanced coating comprised of a nano-structured ceramic to overcome these barriers by (1) reducing the onset of frost formation, (2) slowing the rate of frost growth, and (3) enhancing the removal of frost. The project's goal is to advance the Technology Readiness Level (TRL) of the innovative advanced coating technology from TRL 3 through TRL 5. During this process, the technology will be taken from proof of concept component to an extensively tested at the system level in a laboratory environment to develop the dataset necessary to verify performance prior to future field deployment projects.

Project Benefits

To date there are no anti-ice heat exchanger technologies available for industrial refrigeration heat exchangers. Previous research into anti-ice coating technologies have relied on polymers and fluorinated-compounds which are brittle at low temperatures, are not durable under the thermal cycling, and/or not chemically stable to the cleaning requirements in the industrial refrigeration sector. The competitive advantage of Nelumbo's advanced coating over other attempted anti-ice coatings is that it is a durable ceramic that is chemically bonded to the surface. The ceramic utilizes both surface chemistry and nanostructuring to reduce the rate of ice formation and repel water. It is thin, conformal, durable, and strongly bonded to the surface which allows the coating to flex during the expansion and contraction which occurs during freeze and defrost cycles.

Lower Costs


Internal testing at Nelumbo has shown 14% reduction in system electricity demand over conventional defrosting methods.

Key Project Members

Project Member

David Walther

Match Partners


Nelumbo Inc.


Contact the Team