Bulletin No. 25 - Heat Transfer Fluids

Heat Transfer Fluids: Uses and Potential Problems

What is a Heat Transfer Fluid?
A heat transfer fluid is a substance used to add or remove heat from a process fluid.  Cooling water, steam, ethylene glycol (anti-freeze), halogenated hydrocarbons (refrigerants such as R-22 or R-134a), and even air are examples of fluids used to transfer heat to or from a process fluid.  However, this bulletin will concern itself only with the organic, proprietary fluids used for specialized applications in the CPI.

The heat transfer fluids discussed in this bulletin are organic compounds, typically aromatics, alkylated aromatics, and some high molecular weight glycols.  The differences among these compounds account for the differences in their range of applicability and the potential problems that can take place when using these fluids.

They are used in place of the more commonly used fluids such as steam or cooling water because they have well defined physical and thermal properties that can be more effectively used to control the temperature of the process fluid being heated or cooled.  The manufacturers of these fluids typically offer 6-10 different fluids to achieve the user’s heat transfer requirements.