Sbir phase II: high-efficiency retrofit dehumidifiers for air conditioners via a novel filtration technology

Federal Cooperative Agreement Summary

Helix Earth Technologies Inc. received a $1.25M Cooperative Agreement award from the National Science Foundation (NSF) Technology, Innovation, and Partnerships (TIP) program (CFDA 47.084), effective July 1, 2025 through June 30, 2027. The company is developing high-efficiency retrofit dehumidification systems designed to significantly reduce energy consumption in commercial air conditioning (AC) units. The technology leverages a novel liquid desiccant spray reactor combined with a pressure-swing regeneration system to pre-dehumidify outside air before it enters AC systems, potentially reducing AC energy use by up to 50% while maintaining drop-in compatibility with existing heating, ventilation, and air conditioning (HVAC) infrastructure.

The project's key innovation centers on two technical advances: a novel deployment method utilizing micrometer-scale liquid desiccant droplets with a proprietary multi-scale filtration structure to maximize gas-liquid surface area contact with minimal pressure drop, and a compact regeneration process employing pressure-swing distillation that operates without requiring waste heat. The solution targets the commercial AC market, which exceeds $100 billion annually, and is positioned for rapid market deployment through established HVAC sales and distribution channels.

Abstract

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.- subawards are planned for this award.