Glycol is essential for maintaining efficient and freeze-protected closed loop systems, especially in environments exposed to extreme temperatures. However, not all glycol products are created equal. Selecting the right type of glycol and understanding the available options can significantly impact system performance, corrosion protection, and cost-effectiveness.

Key Takeaways

Not All Glycol is the Same: Ethylene glycol offers better freeze protection, while propylene glycol is safer for systems with food or potable water contact.
All-in-One Products Save Time: Using pre-mixed glycol solutions with built-in inhibitors ensures long-term corrosion protection without additional chemical treatments.
Pre-Mixed vs. Concentrate: Concentrate glycol solutions offer more flexibility and cost-efficiency in terms of transport, storage, and system customization.
Corrosion Inhibitors Matter: Nitrite and molybdenum-based inhibitors are more versatile than phosphate-based ones, especially in systems using hard water.

Is All Freeze-Protection Made the Same?

Most people know that both ethylene glycol and propylene glycol can be used for freeze protection in closed loop systems, but these two products have significant differences:

Ethylene Glycol: Ideal for low-temperature environments due to its extremely low freezing point, but it is toxic, making it unsuitable for applications where it may come into contact with potable water or food.
Propylene Glycol: Safer and non-toxic, this glycol is often used in food-related environments but has a higher freezing point than ethylene glycol. It’s the better choice for environmentally friendly applications or where human exposure is a risk.

Understanding these key differences is crucial in choosing the right glycol for your system’s specific needs.

Pure Glycol vs. All-in-One Products

Pure Glycol

Pure glycol contains no additives. While it may be less expensive upfront, it requires additional corrosion inhibitors and pH buffers to protect the system’s metal components and ensure longevity. Many facilities that choose pure glycol often face higher long-term maintenance costs due to the need for these supplementary chemicals.

All-in-One Products

All-in-one glycol products, on the other hand, are pre-mixed with corrosion inhibitors and pH stabilizers, providing complete system protection from the start. This option offers more convenience and fewer headaches, as it eliminates the need for adding extra chemicals. The right all-in-one blend can also extend the life of your system by preventing common issues like corrosion and scaling.

Pre-Mixed vs. Concentrate: What’s the Right Choice?

Pre-Mixed Glycol Solutions

Pre-mixed glycol solutions are ready to use right out of the container, making them a convenient choice. These products are diluted with deionized water to achieve the correct glycol-to-water ratio. However, purchasing pre-mixed solutions may increase overall costs since you’ll need to buy higher volumes, leading to increased shipping and storage needs.

Concentrate Products

Concentrated glycol is undiluted and offers more flexibility. By adding the concentrate directly to your system, you can customize the water-to-glycol ratio to your system’s specifications. Concentrates are typically more cost-effective, as they reduce shipping costs and can be easily transported and stored. You can also dilute concentrates with hard water, which can provide both anodic and cathodic protection in the system.

Phosphate-based vs. Nitrite/Molybdenum-based Inhibitors

Phosphate-Based Inhibitors

Phosphate-based corrosion inhibitors are commonly used in glycol solutions. They provide excellent pH buffering and corrosion protection but have some drawbacks. When used with hard water, phosphate can react with calcium, causing scale buildup inside the system. This reduces the system’s efficiency and may lead to costly repairs over time.

Nitrite and Molybdenum-Based Inhibitors

Nitrite and molybdenum-based inhibitors offer the same level of corrosion protection as phosphate-based ones but are far more versatile. These inhibitors can be used with both soft and hard water, preventing the formation of calcium phosphate scale. They also help protect metal components from corrosion, making them an ideal choice for systems where water quality is inconsistent.

Which Glycol Product is Right For You?

When selecting a glycol product, it’s important to consider your system’s specific needs. If you’re looking for convenience and long-term protection, an all-in-one glycol product with built-in nitrite or molybdenum inhibitors may be the best option. These products reduce the need for additional chemicals and can protect your system from corrosion, scale, and other issues over time.

Before purchasing any glycol product, it’s a good idea to assess the current condition of your closed loop system. Regular testing and monitoring can help ensure that your system maintains the correct glycol concentration and corrosion protection over time. If you’re unsure which product is right for your system, consult a water treatment expert for advice.

Conclusion:

Selecting the right glycol product for your closed loop system is critical to ensuring long-term efficiency, performance, and protection against corrosion and freezing. Whether you opt for ethylene or propylene glycol, the decision between pure glycol or all-in-one solutions, and the choice of corrosion inhibitors, can greatly affect your system’s operation and maintenance costs.

For most facilities, all-in-one glycol products with nitrite or molybdenum-based inhibitors offer the best combination of convenience and reliability. These products simplify maintenance by providing both freeze protection and corrosion prevention, ensuring your system runs smoothly year-round.

However, each system is unique. A thorough assessment of your system’s current state is essential to choosing the right product and avoiding unnecessary costs. Regular testing and monitoring will help maintain optimal glycol levels and protect your system from long-term

A Glycol Buying Guide for Closed Loop Systems