K. Nithyanandam, R. Pitchumani
Impact Innovations LLC,
United States
Keywords: slippery, coating, durability, heat transfer, fouling, solid-infused surfaces
Summary:
Cooling water demand is a critical sustainability challenge across thermoelectric power generation, commercial HVAC and hyperscale data centers, and is projected to grow sharply with the expansion of artificial intelligence (AI) technologies. In the US alone, cooling systems account for 40-50% of freshwater withdrawal (~50,000 billion gallons annually), of which ~3000 billion gallons are consumed and no longer available for downstream use. A large scale data center can consume up to 2 billion gallons per year, equivalent to the water use of 50,000 people. Most of this water is used in condensers, where performance is limited by filmwise condensation and fouling from mineral or biological deposits. These inefficiencies are compensated by circulating large volumes of cooling water, which increases water withdrawals, consumptive losses, pumping energy and thermal discharges that harm aquatic ecosystems. Our innovation is a patent-pending, retrofit-ready non-wetting surface coating produced via low-cost, scalable fabrication. By sustaining high-efficiency dropwise condensation heat transfer and providing superior resistance to mineral and biological fouling, these surfaces provide measurable water and energy savings, higher operational efficiency, reduced downtime, and lower OPEX. We successfully demonstrated scalable fabrication of solid-infused surfaces (SIS) using low-cost electrodeposition and etching across diverse materials, including copper, aluminum, stainless steel, Monel, and Inconel. Laboratory testing confirmed durability under heated immersion, flowing water, and abrasive conditions representative of industrial condensers. SIS-coated tubes sustained stable dropwise condensation with a four- to five-fold increase in condensation heat transfer, maintained over extended operation. Flow loop experiments further showed >30% reduction in mineral fouling compared to bare surfaces. Techno-economic analysis indicated SIS can cut condenser lifetime cost by over 40% and cooling water requirements by 50–60%, reducing freshwater withdrawals, consumptive losses, pumping energy, and thermal discharges. The presentation will summarize our R&D efforts in the development of this novel durable, non-wetting surface solution.