Chilled Water Systems: 50 Years of the Engineers Newsletter

The first-of many Trane Engineers Newsletters on chilled-water systems were published in 1973 with concentration on chilled and condenser system piping design. At that time, chilled-water systems had a constant-flow design. This began to change in the late 1970s as a new technology, the variable speed drive, was applied to chilled-water pumps. To educate the industry, “A Need for Variable Flow Chilled Water Systems” (1977), “Water Chiller (Control): Decoupler Variable Flow Systems” (1979), and “Chillers are Constant Flow Devices” (1980) were published. These articles provided background on primary-secondary (decoupled) systems which operated more efficiently and became common design practice for the next decade.