Solar Powered Liquid Desiccant Air Conditioner for Low-Electricity Humidity Control

The air-conditioning AC technology of today is primarily based on direct expansion DX or the refrigeration process. It is now so prevalent that it is considered a necessity for the majority of residential and commercial buildings throughout the United States. During the 100-plus years of development, DX AC has been optimized for cost and thermodynamic efficiency, both of which are nearing their practical limits. Nevertheless, AC accounts for approximately 15 percent of all source energy used for electricity production in the United States alone nearly 4 quadrillion British thermal units Btu, which results in the release of about 343 million tons of carbon dioxide into the atmosphere every year Department of Energy DOE, 2011. The Department of Defense DoD occupies over 316,000 buildings and 182,000 structures on 536 military installations worldwide, and accounts for about 64 of the energy consumed by federal facilities. This makes the DoD the largest energy consumer in the United States. In Fiscal Year FY 2007, the DoD consumed 218 trillion Btu in site-delivered energy, 26.2 trillion Btu for AC alone. This cooling cost equates to an estimated 413 million per year Pacific Northwest National Lab, undated. In hot, humid climates, conventional AC units expend energy to sensibly overcool the air in order to provide dehumidification. As a result, additional energy must be used to reheat the air to a more comfortable supply temperature overcoolreheat cycle. The use of desiccant-based AC systems decouples the latent and sensible loads of an airstream, enabling higher efficiency cooling and improved thermal comfort conditions. Liquid-desiccants are solutions that are hygroscopic but are easily able to be pumped and applied within heating, ventilating, and air conditioning HVAC equipment as necessary.