SBIR Phase II: High-Efficiency Retrofit Dehumidifiers for Air Conditioners via a Novel Filtration Technology

The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase II project lies in the development of high efficiency retrofit dehumidification systems that can significantly reduce the energy consumption of commercial air conditioning (AC) units. Traditional commercial air conditioners cool incoming outside air, which often carries a high humidity load that adds a significant parasitic load to the system. By addressing the inefficiencies of traditional dehumidification methods, this technology has the potential to cut AC energy use by up to 50% by pre-dehumidifying outside air, leading to substantial cost savings for businesses. The addressable market for commercial air conditioning exceeds $100 billion annually. The commercial viability of this technology is reinforced by the drop-in compatibility with existing AC infrastructure, enabling rapid deployment through established Heating, Ventilation, and Air Conditioning (HVAC) sales and distribution channels. The intellectual merit of this project is rooted in the development of an advanced dehumidification process, powered by a liquid desiccant spray reactor and a pressure-swing regeneration system. This approach differs from conventional methods through two key innovations. First, a novel deployment method for liquid desiccants that maximizes gas-liquid surface area using micrometer-scale droplets for high-rate dehumidification has been developed. This process is enabled by a novel droplet filtration method utilizing multi-scale filtration structures that efficiently capture and absorb fine droplets at a very low pressure drop. Second, a compact, energy-efficient regeneration process that utilizes a pressure-swing distillation system to regenerate desiccant solutions without requiring waste heat has been demonstrated. The objective of this work is to advance this technology to a high-fidelity, pre-commercial system through extensive lab-scale development and pilot and field testing. In addition, this effort will focus on design for manufacturability to ensure cost-effective scaling of the dehumidifier technology developed in this work. The outcomes of this research will enable the first commercial deployments of this breakthrough technology, setting the stage for broader market adoption and widespread energy savings in AC applications. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.