Ethylene Glycol is used for most HVAC applications because of its antifreeze properties, and its desirable solvent and lubricant properties. With an operating temperature range of -50°C to 165°C, this is the most widely used fluid for heating and cooling applications.
Ethylene Glycol functions as a very efficient heat exchange media, superior to propylene glycol. In general a 20% ethylene glycol solution will result in a 6% loss of heat transfer whereas a 40% glycol solution will result in a 14.5% loss of heat transfer. Ethylene glycol should not be used where it could contaminate potable water, food processing or other products meant for human consumption.