Liquid desiccant cooling uses aqueous solutions, typically lithium chloride or lithium bromide, to absorb water vapor directly from air through moisture-absorbing liquid contact. The technology provides simultaneous latent and sensible cooling when the hygroscopic liquid reaches saturation, requiring regeneration through heating. Liquid desiccant systems achieve humidity reductions of 25-35 grains per pound across full climatic operating ranges.
Technical Details
Liquid desiccant solutions circulate through direct contact cooling towers or spray chambers at concentrations of 35-45% salt by weight, extracting 0.8-1.5 pounds of moisture per hour per thousand CFM. The liquid regenerates at 140-180°F heat input using natural gas, solar thermal collectors, or waste heat sources. Regeneration efficiency improves with counterflow tower configurations and desiccant temperature differential optimization. Solution replacement intervals extend 3-5 years when proper water treatment and corrosion inhibition protocols receive implementation.
Applications and Practical Significance
Liquid desiccant systems excel in moderate to high humidity climates where conventional dehumidification proves inefficient. Indoor air quality improvements result from elimination of mold and microbial growth within ductwork and equipment. Data centers and laboratories benefit from direct moisture removal without recirculation contamination risks. Hybrid desiccant-evaporative cooling arrangements optimize performance across climate variations, supporting energy efficiency targets in humid regions where traditional desiccant applications prove limited.