Inhibited vs. Uninhibited Thermal Fluids

Glycol fluids provide excellent thermal properties for water-based HVAC or cooling systems by significantly reducing the freeze point of water.  Without glycol, these systems would seize up & expand dramatically, leading to deformed pipes or burst connections. 
 
However, glycol chemistry can degrade overtime leading to the formation of organic acids especially if the fluids are exposed to high temperatures. Along with the formation of acid, there are several components that can lead to challenges: 

The presence of these acid byproducts can reduce the overall pH of the system resulting in higher corrosion rates and system damage.  Without the proper concentration of inhibitors in the fluid the metal surfaces are left unprotected, and the initial savings on the home-brew fluid become a drop in the bucket compared to the costs incurred to repair or replace the system itself.

Dow Chemical has decades worth of proven performance in expertise in the thermal fluid industry. Their specially engineered inhibitor packages ensure excellent protection from corrosion and best-in-class long term operation.

The table below details the protective performance of water, uninhibited glycols (propylene & ethylene) and properly inhibited thermal fluids DOWFROST™ and DOWTHER™ SR-1. 

Note: Based on ASTM D1384. The test data listed is intended for screening purposes only.  Corrosion rates in excess of 0.5 mils per year (2.5 mils per year for aluminum) are generally not considered adequate protection.  Samples with a + showed a weight gain.