University of California case study for Beale Air Force Base Contrails Dining Facility in Marysville, California.EvaporCool pre-coolers were installed on a 50-ton air-cooled chiller at the 15,000 sq. ft. Facility. The project demonstrated the peak-time energy savings, energy savings per year and dollar savings per year for a conÂdenser air pre-cooler over a multitude of possible facility sizes served, and over a large range of chiller and RTU capacities (25- tons to 200-tons) for climate zone 11.
Standard air-cooled, vapor-compression cooling systems become less efficient and less effective when they are needed most: when it’s hot outside. This is because the compressor must work harder to produce a refrigerant temperature high enough to cause heat to flow from the condenser to the hot outside air. This hard work means more energy consumption and more part wear; both lead to increased costs. It also means that cooling causes building electrical demand to peak on hot afternoons; this stresses the grid and can increase building operating costs.
Evaporative pre-coolers are effective retrofits to reduce the temperature of air that cools the condenser coil in air-cooled chillers, RTUs and other DX equipment. In these systems, the outside air stream passes over a wetted surface before it reaches the condenser, heat from the outside air is absorbed by water evaporation thus cooling the air stream. Evaporative condenser pre-coolers are applicable to most all climate zones, but have even more energy impact in lower humidity areas, such as California.
Evaporcool is one such evaporative condenser-air pre-cooler. The system uses a microprocessor controller to manage the spray of filtered domestic water onto an evaporative media. The flow rate of water delivered changes with outside air temperature and relative humidity so that the system delivers roughly only as much water as is needed for evaporation. The system has no sump, and no drain or water bleed.