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™ heat transfer fluid contains specially formulated packages of food grade industrial inhibitors that help prevent corrosion. It is made with DOW PuraGuard™ Propylene Glycol USP/EP, a pharmaceutical grade of mono-propylene glycol with specified purity greater than 99.8%.
When you compare DOWFROST™ industrial inhibited glycol based fluids with other heat transfer options, there really is no comparison.
The quality of the glycol thermal fluid you select will have a direct bearing on the long term performance and maintenance of your systems. You can never be sure if you have both adequate freeze and corrosion protection which leads to inadequate maintenance and you may be compelled to replace your fluid frequently which eventually becomes expensive operationally.
Note: The test data listed are intended for screening purposes only. Corrosion rates in excess of 0.5 mils per year (2.5 miles per year for aluminum) are generally not considered adequate for corrosion protection.
+ - showed a weight gain.
* Based on corrosion test ASTM D1384
Five years ago, a major U.S. city hospital decided to do a change-out of its HVAC system. The specification for the replacement fluid was very loose - propylene glycol plus inhibitor. The contract went to a local home-brew supplier with the lowest bid, an oil jobber known for recycling propylene glycol from the local airport's aircraft deicing systems.
The HVAC system at the hospital was filled with approximately 3,500 gallons of diluted "PG plus inhibitor" solution. In a matter of days, all the joints and seals in the system started leaking. As reported in the local media, an odor of methylene chloride was detected in several areas of a hospital wing. After 24 staff members complained of flu-like symptoms - a common reaction to short-term methylene chloride exposure - 40 patients were evacuated.
How this contaminant came to be in the heat transfer fluid was never determined. It might have come from a dirty tank truck or it might have been in the fluid at the outset. Whether the propylene glycol was a virgin fluid or recycled was also a mystery.
After flushing out the system and repairing all the damaged joints and piping, the hospital contacted the local Dow distributor, who quickly rushed over a bulk shipment of 3,500 gallons of DOWFROST inhibited propylene glycol based fluid. Like all Dow low-temperature heat transfer fluids, DOWFROST fluid is pure-quality, virgin fluid. Dow does not sell recycled glycol-based heat transfer fluids. Within a week of the original leaks, the DOWFROST solution was installed in the HVAC system. Dow has received no complaints from the hospital since.
Using "inhibited" glycol fluid in its HVAC system without knowing the strength or weakness of the inhibitor, or even where the fluid came from, could have proved disastrous to a hospital in another major metropolitan area. The original contractor purchased 7,000 gallons of "ethylene glycol plus inhibitor" from a local distributor. The contractor also contracted to return once a year to test the fluid to ensure it retained the proper amount of inhibitor. As it turned out, the fluid was tested just twice - after the original fill and one year later. After two years had passed without getting the annual fluid checkup they had been promised, a concerned hospital maintenance staff attempted to contact the contractor, only to find that the company had gone out of business. And because the defunct contractor was the only party to deal with the fluid distributor, the hospital had no way of determining where the fluid had come from. The only identifying words on the drums were "ethylene glycol inhibited," with the word "inhibited" written in with a marker pen.
A new contractor was brought in; however, the origin of the fluid still could not be tracked down. Faced with an HVAC system running a mysterious fluid of unknown origin and quality, the new contractor called in the local Dow distributor for help in determining what the contractor was dealing with. The only thing the contractor knew for sure was that it wasn't a Dow fluid. However, the contractor valued the Dow distributor's experience with glycols.
The Dow distributor recognized the drums as those of a small distributor known for making home brews - straight ethylene glycol and an inhibitor of its own - and marketing it as a product equivalent to Dow fluids. The home-brew distributor even went so far as to name its product "EG SR-1." The Dow distributor also sent a fluid sample to Dow's Thermal Fluids Testing Laboratory for analysis. In a week's time, the lab sent back a written report stating that the fluid was in poor condition, unable to provide adequate freeze and burst protection. In fact, the lab found enough sediment in the sample to confirm that the inhibitor content was virtually depleted. If left undetected, the remaining straight ethylene glycol and water eventually would have corroded and rusted out the pipes, requiring replacement. So a potential shutdown of the system was averted. All the analysis and reporting were done by Dow free of charge without any promise from the contractor to purchase a Dow fluid. Because there was too much scaling and sediment in the piping to allow partial draining and fluid replacement, Dow recommended a complete cleaning of the system and a total fluid change-out. The new contractor handled the draining and flushing, then filled the system with a 40% solution of DOWTHERM* SR-1 inhibited ethylene glycol-based fluid and 60% deionized water.
The Dow fluid has been in the system for three years. To ensure proper maintenance of the system, the fluid is analyzed every year by Dow, free of charge.
Just four years after filling its HVAC system with poorly inhibited ethylene glycol-based fluid, the hospital had been forced to incur the cost of another total fill. However, in the three years since DOWTHERM SR-1 fluid was put in, no problems have been reported. And in light of the confirmed ability of Dow glycol-based fluids to provide effective freeze, burst and corrosion protection for 20 years or more with proper inhibitor maintenance, no problems requiring another unexpected change-out are foreseen.