The constant problems of poor control and loss of balance setting is becoming a greater problem with the increased awareness of energy conservation. The luxury of "wild" coils, "hunting" control valves, and improper or impossible balance conditions can no longer be tolerated or accepted as proper design.

We, as design engineers, have continued to design as it was passed on through previous jobs without reviewing the text and test data to determine proper selection of valves. The ASHRAE Handbooks, Piping Design Guides, and all control manufacturers present the proper selection procedures for valve sizing.

Testing and balancing of chilled and hot water hydronic circuits indicate the important problems encountered with valves and valve Sizing. The testing procedures and data substantiate the problems and a need for close scrutiny of present common selection procedure.