SBIR Phase I: Retrofit Dehumidifiers to Enable Greater than 50% Air Conditioner Energy Savings Via Elimination of Latent Loads

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project focuses on the development of retrofit dehumidification systems for air conditioners (AC) to reduce latent loads and save more than 50% of the energy consumed by AC systems. Air conditioners consume more than $230 billion in energy annually worldwide, accounting for more than 4% of total global carbon dioxide (CO2) emissions. The goal of this SBIR Phase I project is to develop a drop-in solution for existing AC infrastructure to enable substantial reductions in energy use and operating costs for AC systems. These drop-in dehumidification systems have the potential to save the industry > $100 billion in energy costs and up to 1 gigaton of CO2 emissions annually. The innovation developed in this project will help mitigate the effects of global climate change, while simultaneously ensuring access to affordable cooling systems globally by helping substantially reduce operating costs for AC systems. The intellectual merit of this project is in its utilization of a droplet filtration method, initially pioneered for space applications. This filtration method enables retrofit dehumidifiers that are powered by a liquid desiccant spray reactor that enables high-rate, high-efficiency dehumidification. The dehumidification approach in this project is differentiated from other state-of-the-art methods on the market today due to the method of liquid desiccant deployment, which enables high surface area contact between liquids and gasses. The filtration method enables high-efficiency dehumidification by capturing nearly 100% of fine droplets (<30 micrometers) at very low pressure drop (<100 Pascals) using three distinct filter length-scales. The meter-scale filters are additively manufactured with millimeter-scale helical pores that enable low-pressure-drop inertial capture of fine droplets, which are absorbed in the micrometer-scale porous medium of the filters via capillary forces. These filters enable dehumidifiers that operate 6-8x more efficiently than other methods on the market today and have very high process rates, resulting in a 20-fold reduction in system volume compared to other technologies. This Phase I project will mature the dehumidifiers from a lab-scale proof of concept to a system prototype for a window-scale AC unit. 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.