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The Importance of Inhibited Glycols

The Case of the Vanishing Contractor 

Daniel Cohen 
Market Developer - Dow Glycol Heat Transfer Fluids 

It is critical to use the proper inhibited glycol fluid in applications like HVAC systems. Using a fluid without any knowledge of its deficiencies or the strength of the inhibitor can be disastrous and costly. A similar situation occurred at a hospital not so long ago, where a contractor had purchased 7,000 gallons of fluid from a small distributor. During that time, he was contracted to return the solution for testing each year to ensure the product retained proper inhibitor levels.

Years later, it was found that the heat transfer fluid had rarely been tested after the initial fill. The discovery occurred when an attentive staff member attempted to reach out to the contractor, only to find that the company had gone out of business. Unfortunately, the defunct contractor was the only person who had dealt with the fluid distributor, so the hospital was unable to determine where the fluid came from.

The hospital decided to bring in a new contractor; however, the source of the fluid still could not be located. Faced with an HVAC system operating on a fluid of unknown derivation and quality, the new contractor contacted a nearby Dow distributor for assistance. The contractor knew the fluid was not a Dow product but valued the distributor's extensive knowledge and experience of propylene glycols and their various applications.


Eliminating Shutdowns with Dow Thermal Fluids

The knowledgeable distributor discovered that the drums belonged to a small distributor known for creating their own homebrews with straight ethylene glycol with a less-than-satisfactory corrosion inhibitor. This small distributor would even market their inadequate grade as equivalent to Dow's and even named their product "EG SR-1."

The Dow distributor sent a sample of the solution to be analyzed. The lab at Dow sent a report back stating that the heat transfer fluid was in critical condition and could not provide proper freeze and burst protection. The lab also found enough sediment in the sample to confirm that the inhibitor content was virtually depleted, leaving the system vulnerable to corrosion.

If the remaining straight ethylene glycol and water had not been analyzed, the pipes would have rusted out, causing a potential system shutdown. Luckily, the situation was averted by simply testing, and all the analyses and reporting were done by Dow free of charge. They found too much scaling and sludge accumulation in the piping to allow partial draining and liquid replacement. Dow advocated for a complete system cleaning and a total fluid change out.

The new contractor took on the challenge of emptying and flushing the system completely, then filling it with a proper grade of propylene, a solution of 40% DOWTHERM™ SR-1 inhibited ethylene glycol-based fluid and 60% deionized water. The Dow propylene glycol solution has been in the system for three years now and is analyzed free of charge by Dow each year to ensure proper system maintenance.

Only four years after filling its HVAC system with poorly inhibited solution, the hospital incurred the cost of a complete drain and another total fill. However, in the few years since the DOWTHERM™ SR-1 fluid was put in, no problems or corrosion of any kind have been reported. Dow glycol-based fluids have proven to provide effective freeze, corrosion, and burst protection for decades with proper inhibitor maintenance, eliminating the concern for unforeseen change outs in the future. 

Why Choose a Dow Heat Transfer Fluid?

Dow Heat Transfer Fluids are made out of the highest quality ingredients, backed by detailed analytical and performance data from the world's leading chemical manufacturer.

DOWFROST™ and DOWTHERM™ are specially formulated propylene glycols with highly engineered inhibitor packages to eliminate galling and corrosion for many application types, including closed-loop heat transfer systems. DOWFROST™ is also widely used in process heating and cooling manufacturing applications, like those used in industrial and food and beverage manufacturing. DOWFROST™ HD can also be used in water-based HVAC systems. This is because DOWFROST™ provides fluid longevity and reduces overall fluid expenses since it is made from DOW PuraGuard™, a high-quality propylene glycol with an identified purity of 99.8% or greater.
The quality and grade of glycol selected will directly impact the long-term performance and maintenance of your applications and their systems. Propylene glycol thermal fluids with inadequate corrosion inhibitors often require frequent and total liquid change out, which can be time consuming and costly. To prevent system failure and high associated costs, utilize a trustworthy and food-safe thermal solution like DOWFROST™. DOWFROST™ will provide the necessary freeze and corrosion protection you need to avoid frequent solution replacement and expensive operational losses, and due to its versatile nature, it can be used in many different applications, including food and beverage manufacturing applications. 

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