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The Truth About Glycol in Your HVAC System

by | Jan 31, 2023

Glycol is most often used in HVAC systems as a mixture of water and glycol, known as an antifreeze solution. This solution is circulated through the system to provide protection against freezing temperatures.

Types of Glycol

The two most common types of glycol used in HVAC systems are ethylene glycol and propylene glycol. Ethylene glycol is more commonly used because of its lower freezing point, but it can be toxic to humans and animals if ingested. Propylene glycol is less toxic but also has a higher freezing point. Both propylene and ethylene glycols serve the same purpose of providing protection against freezing temperatures in an HVAC system. While glycol is a great anti-freeze it comes with some drawbacks including energy efficiency and corrosion.

System Efficiency & Corrosion

Glycol’s energy efficiency issues are due to its higher viscosity than water. This increased viscosity means that it takes more energy and pressure to move the fluid around a closed-loop system, leading to higher energy consumption.

Glycol also has corrosive properties that can damage metal components in an HVAC system. It can cause corrosion in the coils, on pipes, valves, and other components over time, which increases maintenance costs.

To ensure you get the most from your glycol solution it is important to regularly check the concentration of both glycol and water in the mixture as well as monitor pH levels. By doing this you can ensure your HVAC system’s anti-freeze protection remains effective and efficient throughout winter months.

What is the True Cost of Glycol?

When deciding whether to use glycol in your system you need to consider it’s cost. The true price of glycol can vary significantly depending on the percentage, system size, and electric cost. You will also want to consider, maintenance costs and additional energy consumption of the fans, pumps, and chiller. Conduct your own energy analysis with our glycol calculator.

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Glycol Alternative

In some cases, alternatives to glycol may be used in HVAC systems – such as Freeze Block Coils. Using Freeze Block technology on your HVAC coils can eliminate the need for glycol. Freeze Block technology senses pressure and temperatures associated with freezing. When these conditions are sensed, the coil will displace a controlled volume of fluid to allow the coil to freeze without damage. When the coil is thawed it will continue normal operation.

When deciding if glycol is right for your system, it is important to consider the cost of installation and maintenance as well as its energy efficiency. Looking into alternatives such as Freeze Block Coils may be an even more cost-effective solution in the long run. Talk with our experts at Cooney Engineered Solutions today to find out what option is best for you!


Perform a Glycol Energy Analysis

Save money and increase efficiency by performing a glycol energy analysis on your HVAC system! Compare the results with an HVAC system that uses water and Freeze Block coils to protect against freezing temperatures, and see which option is best for you!


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