Frequently Asked Questions

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Additives (inhibitors, water, etc.) Freeze and Burst Protection
Color Glycol Definitions and Applications
Concentration Help Placing an Order
Disposal Safety
Dow® Testing Heat Transfer Fluids
Existing Order Assistance Troubleshooting
Food Grade

 

 

 

Additives

Dow heat transfer fluids are fully formulated products when new. They already contain all necessary corrosion inhibitors and performance additives needed to provide long term protection of heat transfer systems. Over time, inhibitors can break down or become diluted and require replenishment. Dow offers a free yearly fluid analysis which will test your fluid and determine any change. Other chemicals or additives should not be added to newly installed Dow heat transfer fluid unless directed to do so by a Dow representative.
Deionized water can be challenging to store because of bacteria and fungi contamination. However, so long as the water tank does not get contaminated and the tank is made from a material that will not corrode, such as HDPE plastic or stainless steel, then deionized water should have an indefinite shelf life. Go Glycol Pros containers are made from HDPE plastic.
Yes, Dow glycol-based fluids contain specially formulated industrial inhibitor packages that are effective in preventing corrosion of metals commonly used in HVAC, food processing and process heat transfer equipment.
Uninhibited or "plain" glycols may seem like an attractive choice because of their relatively low initial cost, but freeze protection is not the only benefit glycol-based fluids provide. Glycols containing inhibitors prevent corrosion of metals and glycols that do not contain inhibitors leave your system at risk. Corrosion presents an ongoing threat to water-based system components and could lead to unscheduled system shutdowns, high maintenance expenses and reduced system life. Inhibited glycol contains industrial inhibitor packages that are effective in preventing corrosion of metals commonly used in HVAC, food processing and process heat transfer equipment.
Deionization and demineralization, while being similar, have key differences. Deionization removes ionized salt from the water. Demineralization removes minerals from the water such as calcium, magnesium and many others. Much of the drinking water that we consume goes through both processes.
Deionized water can be challenging to store because of bacteria and fungi contamination. However, so long as the water tank does not get contaminated and the tank is made from a material that will not corrode, such as HDPE plastic or stainless steel, then deionized water should have an indefinite shelf life.
Uninhibited or "plain" glycols may seem an attractive choice because of their relatively low initial cost. But freeze protection is not the only benefit glycol-based fluids provide. Glycols containing inhibitors prevent corrosion of metals. Corrosion presents an ongoing threat to water-based system components and could lead to unscheduled system shutdowns, high maintenance expenses and reduced system life.
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Color

In special cases, a different dye color for your glycol may be required. In this event, please contact Go Glycol Pros for exact requirements.
Yes, we sell ethylene glycol which is fluorescent pink in color. Note that not all manufacturers may use the same color. If ever a question, we recommend testing the fluid in your system to ensure accuracy.
Yes, we sell propylene glycol which is bright yellow to green in color. Note that not all manufacturers may use the same color. If ever a question, recommend testing the fluid in your system to ensure accuracy.
DOWTHERM™ SR-1 Inhibited Ethylene Glycol is fluorescent pink in color, DOWFROST™ HD Inhibited Propylene glycol is bright yellow to green in color and DOWFROST™ Inhibited Food Grade Propylene Glycol is water white (colorless). Note that not all manufacturers may use the same color. If ever a question, recommend testing the fluid in your system to ensure accuracy.
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Concentration

Water used to dilute glycol-based heat transfer fluid must meet certain minimum standards for purity. Impurities in dilution water can increase metal corrosion, aggravate pitting of cast iron and steel, reduce the effectiveness of corrosion inhibitors, increase inhibitor depletion rate, cause formation of scale and other deposits on heat transfer surfaces, and cause clogging of system components. Distilled or deionized water is recommended. We sell deionized water in 5 gallon pails, 55 gallon drums and 275 gallon totes.
Dow® offers its customers a free yearly fluid analysis which tests fluid samples to determine current inhibitor and glycol levels, plus their recommendations for maintaining proper corrosion protection and thermal performance capabilities. You can learn more about the fluid analysis kit here. For faster, on-site testing, use a refractometer to measure the glycol solution concentration. This instrument requires only a few drops of fluid for testing and requires no adjustment for fluid temperature.
If you do not know how many gallons of 100% concentrated glycol you will need to add to your system to reach your necessary system concentration, try our Concentration Correction Calculator. Once you have determined the volume of glycol needed, follow our step-by-step instructions here.
Use our helpful glycol Concentration Correction Calculator to determine the amount of 100% concentrated glycol you will need to add to your system to reach a desired percent concentration.
The concentration of glycol needed depends on the type of cold weather protection you will require. There are two basic ratings: Freeze Protection and Burst Protection. Freeze protection is required in systems where fluid must continue pumping at the lowest anticipated temperature. Burst protection is sufficient if the system will remain dormant when the temperature drops below freezing and there is adequate space to accommodate the expansion of an ice/slush mixture. To learn more about these two types of cold weather protection and to determine your required concentration, try our Concentration Calculator.
The most cost effective concentration for your system will be the lowest concentration of fluid that meets your cold weather protection requirements. There is no benefit to using a higher concentration than what you'll need in order to provide the necessary cold weather protection to avoid system disruption or pipe burst. Not only will you be paying more for fluid that you didn't need, but excess concentrations of glycol fluid in water can cause your heat transfer efficiency to suffer. The less glycol used, the higher the relative heat transfer efficiency of the solution since glycol has a higher viscosity than water. For these two reasons, we recommend you calculate the exact required percentage concentration required for your lowest possible ambient temperature. We have made it easy with our Concentration Calculator.
The concentration of glycol needed depends on the type of cold weather protection you will require. There are two basic ratings: Freeze Protection and Burst Protection. Freeze protection is required in systems where fluid must continue pumping at the lowest anticipated temperature. Burst protection is sufficient if the system will remain dormant when the temperature drops below freezing and there is adequate space to accommodate the expansion of an ice/slush mixture. To learn more about these two types of cold weather protection and to determine your required concentration, try our Concentration Calculator.
To obtain maximum heat transfer efficiency while achieving adequate freeze protection, avoid using excess concentrations of glycol fluid in water. The less glycol used, the higher the relative heat transfer efficiency of the solution since glycol has a higher viscosity than water. However, you must use enough glycol to provide the necessary cold weather protection to avoid system disruption or pipe burst. For these two reasons, we recommend you calculate the exact required percentage concentration required for your lowest possible ambient temperature. We have made it easy with our Concentration Calculator.
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Disposal

Improper handling and disposal of glycol can pose serious health and environmental risks. Find our handling and disposal instructions here.
Containers in good condition can be rinsed and returned to Go Glycol Pros for a partial credit through our Container Return Program. If you do not wish to return the containers to us, note that our pails, drums and totes are made of #2 HDPE plastic which is widely accepted by local recycling programs. You can learn more here.
Spent glycol, or waste glycol, must be properly disposed of. Improper handling and disposal of glycol system fluids can pose serious health and environmental risks. While we do not offer a service to haul away old glycol, instructions for disposal and locating a waste removal service can be found here.
Spent glycol, or waste glycol, must be properly disposed of. Improper handling and disposal of glycol fluids can pose serious health and environmental risks. You can find our handling and disposal instructions here.
We do not recommend that any glycol be poured down the drain. You can find our glycol handling and disposal instructions here.
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Dow®

Dow only uses high purity glycol that meets their stringent standards, which is used to create their heat transfer fluids. They follow GMP, FDA and ISO requirements and are audited for compliance. Dow tests every batch of DOWFROST™, DOWFROST™ HD and DOWTHERM™ SR-1, provides COAs for every shipment and maintains a Research & Development lab that is capable of verifying and validating the performance of each product. Quality and purity are guaranteed. There are several other brands of glycol that claim they offer the same quality, but sell for a much lower price. Unfortunately, we have found that this lower price denotes lower quality. Instead of using pure glycol, many of these brands use recycled or less concentrated glycol. For example, glycol obtained from waste Aircraft deicing fluids. And because they often do not have the analytical equipment to perform the testing that Dow customers benefit from, the technical data portrayed is often based on other brands' published product performance.
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Existing Order Assistance

Yes, if the item meets certain requirements. You can find our return and exchange policy here.
Yes, if the item meets certain requirements. You can find our return and exchange policy here.
Yes, unused and unopened glycol that meets certain requirements can be returned. You can find our return and exchange policy here.
You can contact us by any one of the methods listed here.
If you are tax exempt, please email your tax exemption certificate to taxexemption@goglycolpros.com after your order has been submitted. Upon processing, which can take up to 2 business days, the sales tax charged on your order will be immediate refunded. Note that we may not charge sales tax in your state at this time. If you do not see sales tax listed on your order total, tax will not be charged and you do not need to submit for exemption.
Containers should be rinsed out with water (plain water is acceptable), ensuring that the glycol-contaminated water used to rinse is poured into an approved waste receptacle.
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Food Grade

Yes, DOWFROST™ propylene glycol is a certified food grade glycol.
DOWFROST™ heat transfer fluid is made from USP/EP grade propylene glycol and food grade phosphate. These two ingredients are generally recognized by the FDA as safe. Based on this regulatory status and the long history of satisfactory use, Dow® certifies that this product is acceptable for use as a heat transfer fluid where contact with drinking water is possible, or food processing applications where accidental contact with food or beverage products could occur.
Industrial Grade is a classification for reduced quality heat transfer fluid, often made from recycled aircraft deicing fluid, or other possible waste streams that are converted into propylene glycol. Industrial grade product is not made with USP/Food Grade glycol, and is therefore a lower quality product. Bargain brand glycols come at a lower price point and a lower dependability than the high purity glycol in Dow® brand glycol-based fluids.
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Freeze and Burst Protection

Solutions in water provide freeze protection to below -60°F (-50°C). You can calculate the exact freeze point of a specific product here.
Solutions in water provide burst protection to below -100°F (-73°C). You can calculate the exact burst point of a specific product here.
Solutions in water provide freeze protection to below -60°F (-50°C). You can calculate the exact freeze point of a specific product here.
Solutions in water provide burst protection to below -100°F (-73°C). You can calculate the exact burst point of a specific product here.
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Glycol Definitions and Applications

No, using automotive antifreeze in your HVAC heat transfer fluids is not recommended. The inhibitors in automotive antifreeze contain silicates that coat heat transfer surfaces with a thick silicate gel that reduces heat transfer.
Yes. Food Grade propylene glycol-water solution, such as DOWFROST™, is an acceptable type of heat transfer fluid in a Geothermal Vertical Closed Loop installation. For additional details, click here to download Best Practices for Geothermal Vertical Closed-Loop Installations from the Michigan Department of Natural Resources & Environment.
Yes, antifreeze is another word for ethylene glycol and propylene glycol. However, antifreeze used for automotive applications is quite different and should not be confused with ethylene or propylene glycol. Do not use automotive antifreeze in your piping system.
Coolant is a mixture of glycol (also known as antifreeze) and water. Antifreeze or coolant used for automotive applications is quite different and should not be confused with ethylene or propylene glycol. Do not use automotive antifreeze in your piping system.
Concentrated glycols are made of almost 100% glycol. For example, Dow® inhibited propylene and ethylene glycols are composed of at least 94% glycol. The remaining 6% (or less) is made up of important corrosion inhibitors and purified water. This mixture is called concentrated inhibited glycol. When you purchase 275 gallons of DOWFROST™ HD for freeze protection up to -1° F, we would recommend you buy a premixed solution of 40% glycol (and 60% deionized water). Your 275 gallons of fluid contains 110 gallons of concentrated glycol (or 40%) and 165 gallons of deionized water (the remaining 60%). The 110 gallons of Dow glycol are pure (94% glycol and 6% inhibitors). Many companies sell lower purity (less concentrated) glycol, meaning that instead of a composition weight of 94% glycol in the unmixed form, you are buying a fluid that contains a lot of additives. The resulting composition weight of the glycol is more like only 65-70% glycol. A less concentrated glycol is less effective because customers assume they are buying 40% of a concentrated glycol mixed with deionized water, but when you take into account the diluted glycol composition, their mixture actually ends up to be only 28% glycol and 72% water. The lower price makes sense because you are buying 12% less glycol. Unfortunately, these companies do little to make it known that they are selling less concentrated product, hoping that this will be overlooked by a more attractive sticker price. The danger in this bait-and-switch is that your system will not be protected to the lowest anticipated temperature. 28% glycol only protects to about 15° F.
Dow® only uses high purity glycol (that meets their stringent standards) to create their heat transfer fluids. They follow GMP, FDA and ISO requirements and are audited for compliance. Many bargain brands claim they offer the same quality glycol, but sell for a much lower price. Unfortunately, we have found that this lower price often means lower quality. Instead of using pure glycol, many of these brands use recycled or less concentrated glycol. For example, glycol obtained from waste aircraft deicing fluids. And because they often do not have the analytical equipment to perform the testing that Dow customers benefit from, the technical data portrayed is often based on other brands' published product performance.
The two primary differences of propylene glycol vs. ethylene glycol are toxicity and heat transfer characteristics. In applications where toxicity is a concern, propylene glycol fluids are used because of their low acute oral toxicity versus the moderate acute oral toxicity of ethylene glycols. However, where toxicity is not a concern, ethylene glycols are preferred as they are less viscous and therefore provide superior heat transfer efficiency and perform better at lower temperatures. Go Glycol Pros sells DOWTHERM™ SR-1 inhibited ethylene glycol, DOWFROST™ HD inhibited propylene glycol and DOWFROST™ inhibited food grade propylene glycol.
Inhibited glycols have an indefinite shelf life if they are stored at ambient temperature and not exposed to direct sunlight. Uninhibited (plain) glycols have a shelf life of two years. Even when stored at ambient temperature and away from direct sunlight, uninhibited glycol oxidizes over time. By year two, discoloration and increased acidity become visually apparent.
With respect to aluminum boilers, we do not recommend using any of existing glycol based fluids when temperature (either fluid temperature or boiler tube wall temperature) is expected to exceed 150°F.  If temperature limits are not exceeded, then we expect normal fluid life.  If temperature limits are exceeded, then failure of the fluid and/or boiler could occur in as little as 6 months or perhaps as long as 3 years.  The timing will depend on actual temperature as well as other system conditions and/or configurations, e.g. the presence of other metals like copper (potential for galvanic displacement type reactions), or the quality of the dilution water (high chlorides cause excessive attack of aluminum), etc.
The type of glycol you purchase depends on your system operating temperatures, toxicity concerns and necessary heat transfer characteristics. You can find more details on the different types of glycol available here.
Inhibited glycols have an indefinite shelf life if they are stored at ambient temperature and not exposed to direct sunlight. Uninhibited (plain) glycols have a shelf life of two years. Even when stored at ambient temperature and away from direct sunlight, uninhibited glycol oxidizes over time. By year two, discoloration and increased acidity become visually apparent.
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Help Placing an Order

Yes, if you are looking to order 1,000 gallons or more, contact us to order and schedule a tanker delivery direct from Dow®, premixed to your specifications.
Pails and drums are securely shipped on pallets. Totes are self containing, with the plastic containers safely nested into a metal crate. Orders are shipped from our warehouse in Novi, Michigan by one of our preferred freight carriers. Shipping costs will depend on the delivery location and quantity of product ordered. An exact shipping cost will be provided at check out, before purchase, and order tracking is provided via email once your order has shipped.
Glycol is available and ready to ship at either 100% concentration or premixed with deionized water to your required percentage. Orders submitted before 12:00pm usually ship in just one business day. Click here to visit our estimated transit timetable. If a rush order is needed, contact us to determine availability.
If you are adding glycol to your already-filled system as part of regular maintenance, you may find our glycol Concentration Correction Calculator helpful. If you are filling a new system and know your system's total volume, simply order the total system volume in gallons of your required concentration. If you need help determining the necessary concentration (how much concentrated glycol to deionized water by % weight in your heat transfer fluid mixture), use our Concentration Calculator. We sell propylene and ethylene glycol custom mixed to your desired concentration, saving you the extra step of mixing glycol with water on-site. Don't forget our Container Calculator; which will tell you what size containers and how many to order for your volume requirements. If you do not know your system's volume, there are a few different ways to calculate the approximate volume. You can find more details here.
Glycol is available and ready to ship at either 100% concentration or premixed with deionized water to your required percentage. Orders submitted before 12:00pm usually ship in just one business day. Click here to visit our estimated transit timetable. If a rush order is needed, contact us to determine availability.
Typically, most tankers provide a minimum air charge capacity to move glycol short distances. In order to insure that your system can be filled, you will need to identify the required pressure needed to accomplish the fill in your application. If you are not sure, contact Go Glycol Pros and we can help you calculate the amount needed. Once identified, we can insure the tanker delivery is equipped to provide the determined pressure.
Go Glycol Pros offers three different types of heat transfer fluid: DOWFROST™ HD Inhibited Propylene Glycol. Bright yellow in color, DOWFROST™ HD has an operating temperature range of -50°F to 325°F (-46°C to 163°C). In applications where toxicity is a concern, propylene glycol fluids are used because of their low acute oral toxicity vs. the moderate acute oral toxicity of ethylene glycols. DOWFROST™ Inhibited Food Grade Propylene Glycol. Water white or colorless, DOWFROST™ has an operating temperature range of -50°F to 250°F (-46°C to 121°C). DOWFROST™ is made from USP/EP grade propylene glycol and food grade phosphate. These two ingredients are generally recognized by the FDA as safe. Dow certifies that DOWFROST™ is acceptable for use as a heat transfer fluid where contact with drinking water is possible or food processing applications where accidental contact with or beverage products could occur. DOWTHERM™ SR-1 Inhibited Ethylene Glycol. Fluorescent pink in color, DOWTHERM™ SR-1 has an operating temperature range of -60°F to 250°F (-51°C to 121°C). DOWTHERM™ SR-1 is less viscous than propylene glycol-based fluids and therefore provides superior heat transfer efficiency and better low temperature performance. It is preferred for most heat transfer applications where toxicity is of no concern.
Glycol is available and ready to ship at either 100% concentration or premixed with deionized water to your required percentage. Orders submitted before 12:00pm usually ship in just one business day. Click here to visit our estimated transit timetable. If a rush order is needed, contact us to determine availability.
Dow recommends a 2" NPT fitting for connecting your system to the tanker for offloading of fluid. Tankers that Dow uses to deliver glycol typically come with 40 feet of 2" hose used to connect your building to the tanker. If you are not able to provide a 2" connection, we will need to know prior to entering the order.
Blending on site is labor intensive and requires someone strong in math and fractions, and precise with measuring fluids. You will also need some place to mix this large volume of fluids, which can be a huge challenge. Premixing is necessary to ensure that the concentration percentages are appropriate for your system to function properly. Go Glycol Pros offers custom premixing to your specifications for no additional cost and will deliver straight to your door. It doesn't get easier than that.
We sell 5-gallon pails, 55-gallon drums and 275-gallon totes all made of HDPE plastic.
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Safety

Safety Data Sheets are located on each product page, are shipped with every order and can also be found here:

 

DOWFROST™ HD Inhibited Propylene Glycol 25%, 30%, 35%, 40%, 45%, 50%, 100%
DOWFROST™ HD Technical Data Sheet

 

DOWFROST™ Inhibited Food Grade Propylene Glycol 25%, 30%, 35%, 40%, 45%, 50%, 100%
DOWFROST™ Technical Data Sheet

 

DOWTHERM™ SR-1 Inhibited Ethylene Glycol 25%, 30%, 35%, 40%, 45%, 50%, 100%
DOWTHERM™ SR-1 Technical Data Sheet
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Testing Heat Transfer Fluids

Dow® offers its customers a free yearly fluid analysis which tests fluid samples to determine current inhibitor and glycol levels, plus their recommendations for maintaining proper corrosion protection and thermal performance capabilities. You can learn more about the fluid analysis kit here. For faster, on-site testing, use a refractometer to measure the glycol solution concentration. This instrument requires only a few drops of fluid for testing and requires no adjustment for fluid temperature.
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Troubleshooting

The key to differentiating the two is to use the physical differences with regard to specific gravity and refractive index. Of course, you will need the proper tools to measure both. If you are not sure how to measure these, Dow® offers a free fluid analysis test kit. Simply collect a sample, utilize the test kit, mail in to the Dow lab using a pre-paid label and Dow will provide results including the type of glycol as well as the quality of the sample sent in.
The key to differentiating the two is to use the physical differences with regard to specific gravity and refractive index. Of course, you will need the proper tools to measure both. If you are not sure how to measure these, Dow® offers a free fluid analysis test kit. Simply collect a sample, utilize the test kit, mail in to the Dow lab using a pre-paid label and Dow will provide results including the type of glycol as well as the quality of the sample sent in.
When filling a heat transfer system, or even during its operation, a system may experience foaming problems. Foaming is due to entrained air in the heat transfer fluid, the cause of which is most often either the system's design or a mechanical problem. Some common causes of foaming can be improper system venting during initial fill, pumps that draw air into the system or free-falling glycol into an expansion tank. Contaminated or thermally degraded glycol can also cause foaming problems in some cases.
Sludge is the result of hot fluid coming into contact with air and oxidizing. Precipitates and sludge can also be deposited by solution water that is not pure and lead to localized corrosion. Go Glycol Pros only uses pure deionized water when mixing with Dow® glycols to minimize the risk of sludge. Insuring that your system is cleaned and flushed prior to adding our glycol mix should minimize the risk of sludging.
No. Ethylene and propylene glycol have different fluid, toxicity and heat transfer characteristics that will prevent your system from operating correctly. If you require a food grade propylene fluid, mixing ethylene glycol will create a hazard that requires a complete drain, clean and flush before refilling with correct glycol fluid.
New systems are typically coated with oil, grease or a protective film during fabrication, storage or construction. Dirt, solder flux, and welding and pipe scale can also cause problems. Therefore, a thorough cleaning of new systems is recommended by Dow®. A solution of 1% to 2% trisodium phosphate can be used with water for flushing the system.
When properly maintained, Dow® branded glycol-based heat transfer fluids can last over 20 years.
Prior to adding new glycol to your system, Dow® recommends the following steps depending if your system is new or older. For a new system, clean and flush your system using a 1-2% TSP (Trisodium Phosphate) mixture. For older systems, Dow recommends an industrial cleaner. If you are not sure, we recommend a professional contractor be consulted and utilized to ensure best result.
No, mixing different types of glycol is not recommended. Each type of glycol has different characteristics. Mixing glycols will result in unknown protection, inhibitors and toxicity levels. In the event that different glycols are mixed, you will need to drain, flush and replace. If there is ever a question specific to what your system contains, the Dow® free fluid analysis test kit may be used and Dow will provide a complete report on the fluid tested.
We recommend two methods for estimating system volume of heat transfer fluids. While neither are 100% accurate, they will get you a close approximate volume which can be used to place your order. Learn more here.
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