Deionized Water vs Distilled Water for Heat Transfer Applications

Heat transfer fluids are often diluted with water to achieve the appropriate freeze protection required, and sometimes systems are filled with water alone. Which type of water should be used- deionized water or distilled water?

Deionized WaterDeionized Water

Deionized water is produced by running water through an RO unit, resin bed system, or some similar piece of equipment. This purification process, sometimes referred to as ‘water polishing’, will strip out most impurities and ions in the water, but will leave some essential ions behind. This water is a good choice for using in heat transfer applications, because the impurities have been removed, but some essential ions are still present, which makes it less corrosive. When using deionized water for heat transfer applications, there are no issues with compromising the system, the integrity of the materials, the construction or any heat transfer fluid that may be used. Standard inhibitors can be used. It is also less costly to manufacture deionized water.

Distilled Water

When water is distilled, ALL impurities and ions are completely stripped out of it. Distilled water is truly pure water. However, it is also very ‘hungry’ for some essential ions that it is now lacking. The water will try to pull the necessary ions out of anything it comes into contact with, making it extremely corrosive. Although we don’t recommend using distilled water for heat transfer applications, it can be used, if it is used with the correct inhibitor package. This may mean that a bolstered inhibitor package will be necessary over a standard inhibitor package. If it is used without the correct inhibitor package, it will seek out the ions that it is ‘hungry’ for from the materials and construction in that system and it will begin to erode the system. Distilled water is also more expensive to manufacture. As a result, CORECHEM generally does not blend distilled water with our heat transfer fluids unless by special request.

With other questions about what type of water you should use in a heat transfer application, reach out to a heat transfer specialist today! Or, browse our heat transfer fluids here.

Do I Need To Treat My Closed Loop System for Organic Growth?

Geothermal Installation

Geothermal and chilled water closed loop systems need to be treated for organic growth. Here we offer tips on cleaning and treating your system, and discuss what happens if you don’t treat.

Initial Cleaning Post-Installation:

Closed loop systems should always be properly flushed and cleaned after the initial installation and before the first fill. Oil, debris, and slag left over from welding and construction of the system could easily be present and will circulate through the system after the initial fill if it is not cleaned out properly. When water or heat transfer fluids begin circulating and are then continuously in contact with the debris and contaminants, they begin to take on a microbiological character. Dissolved microbes in the water can turn into the start of corrosion and organic growth in the system.

Ongoing Treatment & Maintenance:

There are many ways leaks may develop in your system. They may develop unnoticed, or after a repair (i.e. digging up a geothermal loop). If dirt or air or any type of bacteria or contamination is allowed into your system through a leak and is not addressed, this is essentially asking for problems. We frequently receive samples of heat transfer fluids for testing that contain some kind of dirt, debris, or microbiological growth in them, as it is a common problem.


Tips on Cleaning and Treating a Closed Loop System to Prevent Organic Growth

After installation is complete, the system should be properly cleaned using either a sodium hypochlorite (bleach) solution or a closed loop system cleaner such as GlycoClean. This will ensure all contaminants are out of the loop prior to the initial fill. A good inhibition package such as GlycoHib I-50 should then be added to the water / glycol solution used in the initial fill. This will circulate in the system as long as the useful lifespan of the product has not been used up and will keep bacteria from growing that may enter the system through potential hidden leaks. In addition to killing off bacteria, it will also create a film on the inside of the pipes to ensure that nothing from the material in the pipe will break down and contaminate the system.

Annually, the fluid in your system should be analyzed, and if the fluid has been ‘spent’ (the useful lifespan used up), the fluid will need to be replaced.


What Happens If I Don’t Treat My System?

If a system is not properly maintained, it is highly likely that problems will begin to multiply over time. Organic growth and corrosion will eventually lead to system failure, pump failure, and/or decreased efficiency of the equipment as the heat transfer-ability of the fluid is lessened through contamination in the system.

With questions about treating your closed loop geothermal or chilled water system for organic growth, or getting your annual fluids analysis, contact us.

Winterizing with GlycoChill+

January 20, 2021

Winterization, and winterization maintenance throughout the winter, is a crucial part of maintaining plumbing and HVAC systems. Hoses and pipes that will not be used during the winter and are exposed to freezing temperatures should be properly drained and stored. Critical systems that will be used during the wintertime must be maintained through use of a glycol antifreeze solution appropriate to the application.

GlycoChill+ glycols offer a broad range of options and solutions as your inhibited glycols of choice for maintaining these crucial systems:

GlycoChill+ ‘P’ Series Inhibited Propylene Glycol: Our GlycoChill+ P Series is a non-toxic heat transfer fluid specially formulated for use in cooling towers, chilled water systems, and closed loop systems such as geothermal. It is designed for use in systems where toxicity is a concern. GlycoChill+ P Series comes in a 100% concentrate product called GlycoChill+ P200, or in various dilutions, and is highly customizable.

GlycoChill+ ‘E’ Series Inhibited Ethylene Glycol: Our GlycoChill+ E Series has superior heat transfer capabilities and is excellent for use in winterizing geothermal loops and closed loop systems where toxicity is not a concern. It is not recommended for use in cooling towers or boilers due to it’s toxicity. Our GlycoChill+ E Series 100% concentrate product is called GlycoChill+ E200. It also comes in various dilutions, and many customizations such as custom dye, packaging, and dilution are available.

GlycoChill+ ‘P-HD’ Series Inhibited Propylene Glycol: Our GlycoChill+ P-HD Series is compatible for use everywhere our P200 is used. The only difference is, it contains bolstered corrosion inhibitors. This is most commonly used in systems that have ‘soft’ or ‘yellow’ metals such as copper. Use our GlycoChill+ P200HD 100% concentrate product, or specify the standard or custom dilution you require. This product is also highly customizable.

GlycoChill+ ‘P-FG’ Food Grade Inhibited Propylene Glycol: Our GlycoChill+ Food Grade product is designed for use in any application where incidental contact with food is possible. It is available as a 100% concentrate product, GlycoChill+ P200FG.

By regularly maintaining HVAC systems, you will extend the life of the system and save on costly system repairs. With questions about the use of GlycoChill+ glycols in specific winterization applications, get in touch with a heat transfer fluid specialist today. We look forward to working with you!

GlycoChill+ Gets a New Look!

December 31, 2019

Exciting news for the New Year!

Our GlycoChill+ line of Glycols is starting the next decade right, with a brand new, 2020-worthy look!

Our exclusive GlycoChill+ brand of inhibited Propylene and Ethylene glycols was created in 2010. For the past ten years, the aqua blue logo has served us well:

Now, it’s 2020 and we’re changing the game with a whole new look! The new logo offers a sleek, refreshing update, and coordinates with our company logo:

In addition to the GlycoChill+ line, GlycoHib I-50, our corrosion inhibitor, and GlycoClean C-70, our system cleaner, will also adopt the new look. Keep an eye out for the new logo on drums, totes, and carboys exiting our warehouses, starting in January. No changes have been made to the formulation of the products, the update is in the look only. Feel free to contact us with any further questions you may have about the change.

View Glycols.

3 Key Benefits of Biobased Propylene Glycol

What do heat transfer fluids, laundry detergent, & packaged foods have in common?

Propylene Glycol is commonly found in all of them!

Propylene Glycol is a very versatile substance, and a top selling item at CORECHEM. Available in both USP and industrial grade, CORECHEM supplies our customers, commonly, with 100% biobased Propylene Glycol. This means that the product has been derived from vegetable glycerin, instead of crude oil.

**(NOTE: Supply of biobased propylene glycol is not guaranteed and dependent upon current market conditions.)**

So is there a difference in biobased Propylene Glycol and petroleum-based Propylene Glycol? And should you prefer one over the other?

Both types of Propylene Glycol have the same molecular structure, and functionality; only trace impurities in the two products will be different. Here, we compile a short list of three key benefits to using biobased Propylene Glycol.

  1. The ‘Feel Good’ Factor: Biobased Propylene Glycol production provides a 61% reduction in greenhouse gas emissions when compared to Propylene Glycol that has been derived from petrochemical production. You can’t see this benefit, but you can feel good about it- so we call it the ‘feel good’ factor!
  2. Pricing Stability: Derivatives of crude oil can experience dramatic price fluctuations in the event of major world events. Prices for biobased products tend to be more reliable.
  3. ‘Green’ Marketing: The bottom-line benefit of ‘green’ marketing in consumer packaged goods is at times a controversial subject. However, according to a recent publication by the Harvard Business Review, ‘Actually, Consumers Do Buy Sustainable Products’. The use of plant derived ingredients in products such as detergents or other cleaners can help substantiate trust-building ‘green’ claims such as ‘sustainable’, ‘renewable’, and ‘plant-based’. In addition, goods that meet a minimum of biobased content may qualify for the ‘USDA Certified Biobased Product’ seal.

When sourcing Propylene Glycol for your application, consider the benefits of using biobased Propylene Glycol. To discuss the source of the Propylene Glycol products you purchase from CORECHEM, reach out to a sales representative today.


View our Propylene Glycol products:

Propylene Glycol Industrial Grade

Propylene Glycol USP Grade

GlycoChill+ Propylene Glycol Heat Transfer Fluid

GlycoChill+ Propylene Glycol Food Grade Heat Transfer Fluid

Which Type of Heat Transfer Fluid Should I Use?

September 10, 2019

CORECHEM carries four types of inhibited Heat Transfer Fluids: a Propylene Glycol-based fluid, an Ethylene Glycol-based fluid, an Ethanol-based fluid, and a Methanol-based fluid. Use this convenient reference chart to determine which type of Heat Transfer Fluid is most appropriate for your needs. Note: Due to product evaporation, our Ethanol and Methanol-based fluids are most commonly used in closed-loop geothermal systems. View our Heat Transfer Fluids here.

Characteristic Propylene Glycol (GlycoChill ‘P’ series) Ethylene Glycol (GlycoChill ‘E’ series) Ethanol (ExoEndosol series)Methanol (GeoChill ‘M’ series)
Operational Temperature Range -50F – 325F -60F – 250FN/AN/A
Heat Transfer-ability Good BetterBestBest
Toxicity Non Toxic ToxicNon ToxicToxic
Flammability Not Flammable Not FlammableFlammableFlammable
Viscous at Low Temperatures? Yes- larger pumps needed Yes- better than P.G.Slight changeSlight change
Susceptibility to Biofouling Susceptible SusceptibleNot SusceptibleNot Susceptible
Reserve Alkalinity Maintenance Required Yes YesNoNo
Ships as HazMat No Only in bulkYesYes
Price Point Highest HigherLowerLowest
Price Stability Fluctuates w/ crude Fluctuates w/ crudeMore StableMore Stable

How to Maintain the Glycol in your Chiller

Have you checked the glycol solution in your chiller system lately?

At CORECHEM, we recommend checking the fluid in your chiller system annually, as part of a regular chiller maintenance schedule. Here’s how to do that:

chiller on roof
  1. First, contact us to request a fluids analysis kit! We’ll mail it to you directly.
  2. The fluids analysis kit comes with a sample collection bottle, fillable label, and instruction sheet. After collection, mail it back to us using the box it came in.
  3. You should receive your results via email within two days of our receiving your sample! See HTF Water Analysis Sample Report – System Check After Initial Fill.
  4. For a routine annual fluid check-up, your report will include the following information:
    • Glycol Concentration: What concentration do you require? Figure out the lowest temperature your system may be subjected to, to determine the desired ‘freeze point’. Then, refer to a Freeze Point Chart (below) to find your desired concentration. If your concentration is too low or high, use our Glycol Concentration Calculators to determine the correct fix. These should be straightforward to use, but if you have any questions, contact us for assistance.

Propylene Glycol Freeze Point Chart

Ethylene Glycol Freeze Point Chart

    • pH level: The pH should be ideally between 8 and 10.  If your pH is too low, you may need to add additional inhibitors, or flush and refill the system, depending on your lab results.
    • Reserve Alkalinity: Your Reserve Alkalinity measurement will help determine whether or not your fluid can be restored. If your Reserve Alkalinity is used up, your fluid’s useful lifespan is over, and you will need to flush and refill the system.
    • Additional Testing: If the initial testing of your fluid doesn’t provide a clear picture of the health of your system, or if you have specific concerns about your fluid, there are additional tests we perform. Additional tests can indicate the presence of bio-fouling or corrosion (i.e. iron or other specific metals present).
    • Suggestions: Our lab analyst gives you full recommendations for your fluid.

If you are concerned about the health of your fluid, or have any other questions about glycol / chiller maintenance, give us a call. We look forward to serving you! You can view all of our heat transfer fluids, including our GlycoChill+ glycols, HERE.

Geothermal Maintenance Made Easy

April 2, 2019

As warm weather returns, it’s time for your spring geothermal maintenance check-up!

At CORECHEM, we recommend you inspect your geothermal system at least once a year. Spring and fall are the most common times to do this. Test in the spring to look for post-winter issues; test in the fall to make sure your fluid concentration is high enough to prevent freezing.

Either way, it’s important to perform a check to detect any small issues your system may be having before they become big – and expensive.

First things first! Do an annual fluids test. A spring fluids test will help detect:

  • the presence of / potential for algae or mold growth (bio-fouling) prior to summer weather
  • the presence of /potential for corrosion
  • whether or not your fluid is ‘spent’
  • underground leaks (One good indicator of leaks is if you have red clay or excessive dirt in your geothermal fluid.)

CORECHEM is making is easy – and fast – to test the health of your geothermal system this spring! Call us today to have a geothermal maintenance test kit mailed to you. Your fluid will be tested for concentration, pH, and reserve alkalinity. Additional testing is performed as needed to further diagnose the health of your geothermal fluid. You should receive your results within 2 days of our receiving your sample!

It is also important to check:

      1. Filters. Clogged filters in your heat exchanger increase wear and tear on your pumps. (Ideally, we recommend checking these at least once a quarter.)
      2. Condensate drain. A clogged condensate drain will impede water flow – causing your pumps to work extra hard.
      3. For visible leaks.
      4. All of your heat pumps, fans, thermostat and other equipment. These should be tested to ensure they are working properly.
      5. Foliage overgrowth. Remove foliage to ensure nothing is obstructing your air intake.

At CORECHEM, we look forward to helping you bring your geothermal fluid up to speed. Call us today to discuss our geothermal fluid products including: glycols, alcohol-based fluids, and corrosion inhibitors.

Flu Shots … and Closed Loop System Checks

We all know that fall is a time to think about our flu shots, and that it is critical to maintain our health during the flu season. Have you considered checking the health of your customers’ closed loop HVAC and geothermal equipment, to ensure that it too stays healthy all season long? CORECHEM Inc. is your resource for analyzing thermal fluids, to give your customer the peace of mind that their systems contain enough antifreeze to protect from a freeze up flu.

Closed Loop System

Why Is It Important to Treat Your System with the Burst Protection Flu Shot?

Winter is once again on the brink, and just like humans, the health of your closed loops systems might suffer. CORECHEM’s GlycoChill+™ and Exo Endosol™ products provide both the freeze and corrosion resistance that your clients’ systems need to stay well all winter long.

From now until November 30, CORECHEM is offering thermal fluid analysis for any system, at no charge! Simply reach out to us at or call 865-524-4239 to have a sample kit shipped to you today. You should get your results within 2 days of the receipt of your sample!

Request a sample test

Heat Transfer Fluids

Heat Transfer Fluids

When it comes to your closed-loop system’s performance, longevity, and long-term maintenance, you can count on from CORECHEM Inc.  As a producer, we supply Heat Transfer Fluids that meet the demanding needs of a variety of industry applications including:


  • HVAC system freeze/burst/corrosion protection
  • Food industry applications
  • Process and equipment deicing
  • Process cooling and heating
  • Ice skating rinks
  • Air preheating
  • Waste heat recovery
  • Sidewalk and walkway snow melting and deicing
  • Sprinkler systems
  • Ground loop heating systems (geothermal)
  • Water chiller systems
  • Central heating systems
  • Pipeline tracing


Questions about application?  Reach out to a heat transfer fluids specialist today to help you find the right solution.