Efficiencies in the inch-pound version

A water chiller is a water refrigeration apparatus that generates cold water to cool down industrial process equipment. The apparatus is a tout ensemble of components including refrigerant, condenser, pipes, coolant expansion, pumps and a reservoir. Water is cooled to cryogenic temperatures and is directed to the process equipment through a hydraulic circuit. These chillers protect water by recycling refrigerant in a closed circuit instead of pumping in water continuously. Some of the areas where these chillers prove their applicability are in packing and printing machines, ozone generators, and as domestic chillers in condensed dimensions. The water-cooled chiller is a cryogenic design that cools entities by transferring heat absorbed from process water to an individual water source such as a river, pond or a cooling tower. These chillers are pertinent in situations where a cooling tower is at immediate disposal, or where a user demands optimal power consumption. They necessitate condenser water treatment to remove mineral buildup, the absence of which causes insubstantial heat transfer, which is antecedent to an inefficient unit. They find application in chemical and pharmaceutical processes, milk and dairy pasteurizing, food products, and plastic processing.
Product development for water cooled chiller system in recent years has focused on improving off-design and part-load performance where most of the operating hours occur, said Drake Erbe, chair of the standard’s mechanical subcommittee. Variable speed drives (VSD) technology has advanced and is finding widespread application in water-cooled chillers. The use of VSDs has led to off-design and part-load improvement of the chiller’s performance with efficiencies of up to 30% in integrated part-load value (IPLV). Under the proposed addendum, an alternative set of efficiency levels, Path B, is established for process water chiller intended for applications where significant time is expected at part load. All Path B chillers must be equipped with demand limiting controls. Under this proposal, compliance with Standard 90.1 can be achieved by either meeting the requirements of Path B or Path A (intended for applications where significant operating time is expected at full load conditions). The proposed addendum also combines water-cooled positive displacement chillers into one category and adds a new size category for centrifugal chillers at or above 600 tons. The air-cooled chiller without condenser equipment type category has been eliminated. All air-cooled chillers without condensers must now be rated with matching condensers. The minimum efficiencies of air-cooled chillers have also been updated, Erbe said. Efficiencies in the inch-pound version of Standard 90.1 are now expressed in energy efficiency ratio (EER) for air-cooled chillers, kW/ton for water-cooled chillers and coefficient of performance (COP) for absorption chillers to reflect industry practices. Tables 6.8.1 H through J listing minimum full load and non-standard part load value (NPLV) efficiencies of sorema water chiller at non-standard rating conditions have been eliminated and replaced by an algebraic equation. The tables will now be included in the User’s Manual.