Analysis of Chilled Water Free Cooling at the Perimeter Center Office Park (Atlanta, Georgia).

摘要

Energy conservation is an important part of any Heating, Ventilating, and Air Conditioning (HVAC) system design and operation today. One of the most common energy conservation measures used in water side economizer systems is free cooling. However, it is difficult to evaluate the potential for savings of the impact of free cooling without a detailed analysis. In order to better understand the potential impact of free cooling operations, data on an existing system from a ten year period was compared with the ambient climatic conditions. As will be discussed, for all but the hottest summer months, free cooling accounted for a significant percentage of the system's operating hours. By comparing actual weather data with the free cooling data, the ambient dry bulb switchover temperature for Atlanta was found. As part of its energy conservation program, the Perimeter Center Office Park in Atlanta, Georgia has used free cooling in the HVAC systems of its low-rise(one to two story) and mid-rise(three to ten story) buildings. The HVAC system for each group of buildings consists of a 150 250 ton central chiller with multizone air handlers and electric duct heating. The system incorporates a water-side economizer using the cooled tower water directly in the chilled water system. In free cooling, the switchover temperature is the dry or wet bulb temperature at which the system switches from its conventional mechanical cooling operation to free cooling.