Heat exchanger coil with tube insert

A method to cool a fluid, comprising:

• providing refrigerant to a coil of piping from a chiller, the coil of piping defining a cylindrical space in a center portion of the coil of tubing;
• returning the refrigerant via a return pipe that receives the refrigerant from the coil of piping and returns to the chiller via path through a central axis of the cylindrical space;
• and
• contacting an insert tube to the return pipe via at least two connection points, wherein the insert tube substantially fills the cylindrical space inside of the coil of piping and surrounds the return pipe,
• contacting the coil of piping and the insert tube with the fluid to be cooled.

A heat exchanger configured to heat a liquid, vapor or other medium, comprising:

• a coil of piping configured to receive a heating medium from a heating source, the coil of piping defining a cylindrical space in a center portion of the coil of tubing;
• a return pipe configured to receive the heating medium from the coil of piping and return to the heating source via a path through a central axis of the cylindrical space;
• and
• an insert tube that has at least two connection points to the return pipe, the insert tube substantially filling the cylindrical space inside of the coil of piping and surrounding the return pipe,
• wherein the coil of piping and the insert tube are configured to contact a fluid to be heated.