The Heat Exchange Institute (HEI) is a non-profit trade association committed to the technical advancement, promotion, and understanding of a broad range of utility and industrial-scale heat exchange and vacuum apparatus.

The primary purpose of HEI is to develop and publish standards which advance the technology, increase the efficiency, and promote the use of heat exchange and vacuum apparatus. Members are involved in various sections focused on technology.

These sections are Air Cooled Condensers, Steam Surface Condensers, Closed Feedwater Heaters, Shell and Tube Heat Exchangers, Plate Heat Exchangers, Vacuum Technology and Deaerator.