HVAC Dew Point Cooling

Dew Point Cooling

The cooling process:

• The StatiqCooler is a heat exchanger that forms the core of an air cooling system.
• The heat exchanger consists of proprietary plates made of polypropylene. Inside these plates there are air channels,  through which primary air is blown, usually fresh ambient air.
• The outside of the heat exchanger plates are covered with a hygroscopic layer, which is externally moisturized by water. Due to forced evaporation of the water on the surface of the plates energy is extracted and this indirectly cools the air inside the channels.
• 100% primary air is cooled in the heat exchanger, 70% of the cooled air is supplied to the space which needs to be conditioned and a 30% of the cooled air is derived as scavenger air in a counter flow along the hygroscopic layer on the outside of air channels in the heat exchanger.

Air-conditioning is the single largest contributor to peak demand on U.S. electricity grids and is the primary cause of grid failures and blackouts.i Power generators and refrigeration-based airconditioning units are least efficient at high ambient temperatures, when cooling demand is highest. This leads to increased pollution, excessive investment in standby generation capacity, and poor utilization of peaking assets. Air-conditioning accounts for approximately 15% of all source energy used for electricity production in the United States alone (nearly 4 quadrillion Btu), which results in the release of about 343 million tons of carbon dioxide into the atmosphere every year. ii Evaporative air conditioners can mitigate the environmental impacts and help meet Energy Independence and Security Act (EISA) 2007 and U.S. Department of Defense (DoD) energy policy goals by eliminating energy waste and reducing electricity demand. Researchers have developed a new multi-staged indirect evaporative cooling (IEC) technology known as the Coolerado Cooler. This technology uses a unique design that maximizes the effectiveness of the direct and indirect stages of its cooling process. The cycle works by cooling both the primary (or product) air and the secondary (or working) air in a 20-stage process. Each stage contributes to cooling by combining multiple direct stages with a single indirect stage. The cumulative result is a lower product air temperature than is possible with conventional evaporative cooling technologies, as the unit can achieve wet bulb effectiveness (WBE) of 90%– 120%. The key difference between this and other direct/indirect processes is that the working air that accumulates moisture is exhausted at each stage, enabling the product air to be delivered at a lower dry bulb temperature. This thermodynamic cycle is referred to as the Maisotsenko Cycle (or M-Cycle). The project objective was to demonstrate the capabilities of the high-performance multi-staged IEC technology and its ability to enhance energy efficiency and interior comfort in dry climates, while substantially reducing electric-peak demand. The project was designed to test 24 cooling units in five commercial building types at Fort Carson Army Base in Colorado Springs, Colorado, to provide an analysis of energy use, water use, energy performance, and interior thermal comfort. The five buildings selected for the demonstration included the training facility, event center, theater, jet aeration facility, and the digester facility. The event center, digester facility, and jet aeration facility did not have air-conditioning prior to the demonstration. The training center was using small spot coolers that did not have sufficient cooling capacity to meet the cooling load, and the theater had an antiquated heating, ventilation, and air-conditioning (HVAC) system that had insufficient capacity. In addition to these buildings, a stand-alone unit was installed at the wastewater treatment plant to test the technology’s ability to operate using gray water.