Advances in Energy Efficiency, Capital Cost, and Installation Schedules for Large Capacity Cooling Applications Using a Packaged Chiller Plant Approach

Abstract

Cooling equipment, whether used to meet air-conditioning or process cooling loads, represents a large consumer of energy. Even more to the point, cooling loads and the associated cooling equipment energy consumption tend to be at maximum levels during periods of high ambient air temperatures. It is precisely at those times that the general demand for energy is at its peak and therefore the price or value of energy is also at its highest level. Cooling loads often drive the peak electric power demand of energy users and thus affect not only the level of consumption of high cost energy, but also affect the peak power demand. Together, the energy and demand costs equate to very high unit costs for operating cooling equipment. Accordingly, it is of interest to minimize cooling energy use and costs by maximizing the energy efficiency of cooling equipment installations. A relatively new approach has been developed and is being increasingly used to maximize chiller plant efficiency. The approach involves the use of a standardized, pre-engineered, shop-fabricated approach to entire chiller plant installations. Compared to the traditional, piece-meal approach to chiller plants that utilize individual component specification, procurement and installation, the "packaged" or modular chiller plant approach often delivers substantially improved energy efficiencies. Also, the packaged plant approach achieves further benefits for large cooling system owners and operators. These additional benefits include: 1) dramatic reductions in unit capital costs of installed chiller plant capacity on a dollar per ton basis, 2) marked improvements in total procurement and installation schedules, 3) significantly smaller space requirements, and 4) enhanced control over total system quality and performance. The capacities and performance characteristics of available chiller plant modules are described, including both electric and non-electric chiller technologies. Examples are presented to illustrate the typical sizes and locations of actual installations as well as the growth and extent of the use of this technology to-date. Case studies document the energy efficiency improvements, cost reductions in both operating and capital costs, and improvements in schedule and space utilization, of the packaged chiller plant approach relative to the traditional chiller plant approach.