Testing and Maintaining Your Glycol Heat Transfer Fluid

March 9, 2020

You have selected a glycol fluid and pumped it into your system along with high quality fill water. Now what? 

Regular glycol testing in HVAC systems is key to avoid unforeseen maintenance costs or unscheduled shutdowns. Somewhere down the road, changes may occur in the system which could affect the heat transfer solution. For example, periodic leaks in the system components or piping may require adding more fluid. The proper course of action would be to add as much glycol fluid as needed to bring the system solution back to the required level of concentration. However, glycol addition often does not happen, especially if the system has an automatic water makeup valve. Proactively testing, observing and maintaining your heat transfer solution on a regular basis will extend the life of your Dow® chemical heat transfer fluids for more than 20 years!

In this article, we will discuss four testing methods you should add to your to-do list today:

  1. On-Site Glycol Fluid Analysis. We recommend self-testing using an on-site fluid analysis tool such as a refractometer monthly.  A refractometer test measures the glycol concentration and gives the glycol freezing point of your solution. This instrument requires only a few drops of fluid for testing and requires no adjustment for fluid temperature. Need to increase your system's concentration (also known as correcting glycol concentration or balancing glycol concentration)? Use our easy concentration correction calculator to find out how much glycol is needed.
  2. Testing Your Glycol pH Level. Control of glycol pH level between 8.0 and 10.0 is important to minimize corrosion and glycol degradation. Using narrow range pH paper is an easy and reliable way to read your pH level. A pH tester can also measure alkalinity or acidity of the fluid. Any fluid with a pH below 7.0 should be replaced. For fluids between 7.0 and 8.0 adjustments can be made using a 50% solution of sodium hydroxide or potassium hydroxide.
  3. Examine the Condition of Your Fluid. Examine your fluid for appearance and odor. Any drastic variation from the initial fluid specifications such as black or dark-gray color, presence of an oily layer, burnt odor or any heavy sludge in the fluid may indicate the need for fluid replacement. Contact us today if you notice any of these signs in your system solution.
  4. Free Glycol Testing From Dow. Customers of Dow heat transfer fluids are backed by comprehensive supporting services. Performed on an annual basis, Dow offers customers a free glycol testing kit. The fluid analysis kit includes everything you'll need to send fluid samples to Dow for an analysis that includes: determination of current fluid inhibitor and glycol levels, plus Dow's recommendations for maintaining proper corrosion protection and thermal performance capabilities. If you have purchased from Go Glycol Pros in the past, you are eligible to receive a free fluid analysis kit. To order your kit today, click here!

Go Glycol Pros LogoGo Glycol Pros is a distributor of DOW® heat transfer fluid for over 20 years. We sell glycol online with no accounts or order minimums required. Available in 275 gallon tote, 55 gallon drum or 5 gallon pail, high purity DOW antifreeze is premixed with deionized water (DI water) at our in-house facility and ships out within just one business day. Our inhibited glycols include: DOWFROST HD propylene glycol, DOWFROST food grade propylene glycol and DOWTHERM SR-1 ethylene glycol.

Explore more helpful tips and advice at goglycolpros.com. Our knowledgeable glycol experts are ready to help you with your latest hydronic HVAC project.

View Dow Ethylene Glycol, Propylene Glycol and Food Grade Propylene Glycol

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Disclaimer: Go Glycol Pros and it’s affiliates can not be held liable for issues caused by use of the information on this page. While the- information comes from many years of experience and can be a valuable tool, it may not take into account special circumstances in your system and we therefore can not take responsibility for actions that result from this information. Please feel free to contact us if you do have any questions.