Glycol ground loop

The Loops… This is probably the simplest portion of the system to understand. Unfortunately, it can also get fairly complicated to plan and install. This is how I set up my Loops. This is the evil Red Loop that leaked. The red nylon rope going up the side of the Loop was one of a few color coding I schemes I used to identify the Loops.

March I would not wind my loops like this again. For me it works fine; but, I think there is too much propensity for a kink. Neither of these are an issue in my setup; however, looking back, this was not a great design. Open systems are pretty easy to deal with UNLESS your water source has a tendency to dry up or run at a very low rate.

Running at a low rate creates problems for the GSHP since they require a certain amount of water going through the system per minute in order to operate efficiently.

If you can not provide a sufficient water flow through out the year, do not consider an Open system. Calculating the size and the amount of pipe that you will need is fairly easy. You will only need one pipe coming in and one pipe going out. Calculating the cost of the pipe based on length is pretty simple. Typically, you will use 1. So, if a stream has 45 degree water running it in year round, the GSHP will get 45 degree water to work with.

Finally, Open systems are generally much easier and cheaper to setup. If you can go this route, please do so. A Closed system circulates the same fluid around and around and around. It works like the cooling system on a car.

The engine warms the coolant up and the radiator cools it down.

TTherm Geothermal Slinky Earth Loop Assembly

The same fluid is used over and over again. A Loop is a long piece of pipe that has fluid circulated in it.There are many applications for high, medium and low temp glycol chillers. Ethylene Glycol EG fluid is a colorless practically odorless, low volatile hygroscopic liquid that does not contain any foreign additives. EG is ideal for recirculation chillers and heaters, and has good rust inhibitors. EG is safe because it has a high flash point of F. Propylene Glycol PG is an excellent antifreeze and fluid transfer medium.

Without a properly designed system and knowing the application, it is possible for the evaporator to freeze-up operating at F supply temperature. Although we install flow safety switches and low pressure safety for freeze protection a system is not fail safe without the right mix of antifreeze fluid protection.

We install our chillers in low flow applications where the chiller is s of feet from the heat load with high line loss. The processor should run antifreeze in this situation but we offer a dual pump option with low ambient head pressure fan cycling with crankcase heater and standard low pressure freeze stat protection.

Another option we provide is a flow switch which interlocked with the compressor. Skip to content. Glycol Chiller Systems.This is very important for closed loop systems that may be exposed to freezing conditions. What is the difference between freeze protection and burst protection? Most systems can handle short periods of slush if the viscosity remains low. As the temperature continues to decrease, the glycol begins to freeze. Unlike water which expands when it freezes, glycol contracts when it freezes.

Therefore, when the glycol freezes, the volume in the system actually decreases. With freeze protection, there will not be any freezing of water or glycol in the mixture. Both types of glycol will provide adequate freeze protection in most systems.

Ethylene glycol is the industry standard for closed loop freeze protection and is the product we use in most applications. Where food or potable water contact may be a concern, specify propylene glycol. Propylene glycol is less toxic, breaks down more rapidly and is more environmentally friendly.

How to add water to a closed loop

Unfortunately, the freezing point of propylene glycol is not as low and its volume remains stable as it freezes and therefore does not offer the burst protection of ethylene glycol. The visual differences may be as follows:. While automotive antifreeze does contain glycol, most brands are formulated to protect the aluminum components found in modern cars. The primary corrosion inhibitor in most automotive antifreeze blends is silicate.

Silicates tend to form thick, visible passivation films that can adversely affect heat transfer. Silicates also tend to be gritty and can shorten the life of pump seals. Any type of corrosion inhibitor will require periodic replacement or supplementation.

Silicate-based corrosion inhibitors have shorter replacement intervals than traditional blends such as SN-7 or SN Most automotive blends also contain fluorescent dyes that make many water chemistry test results impossible to see.

What is the Fluid in a Geothermal Ground Loop, and is it safe?

Since glycol has a lower specific heat than water, higher concentrations of glycol in your closed loop water will reduce the heat carrying capacity of the system.

Too much glycol will, therefore, increase energy costs as the system works harder to accomplish the desired heating or cooling. The glycol in a system does not protect any metal from corrosion. It is only the corrosion inhibitors that are added to the glycol that protect the metal.

The zinc in the galvanizing will react with most inhibitors and cause loss of the zinc coating leading to localized corrosion.Remember Me?

Page 1 of 2 1 2 Last Jump to page: Results 1 to 13 of Thread: Closed Loop Antifreeze. Thread Tools Show Printable Version. Closed Loop Antifreeze Can a pro and con discussion about Geothermal closed loop anti freeze be posted here? I mean, "stuff that will work just fine" vs the commercial stuff?

glycol ground loop

I've heard of RV fluid, windshield washer fluid, moonshine, etc I get it and have my opinion. Can anyone post the truth? I called a few places, I was told, "Sir, I cant answer that, or Sir, your asking a question that I cannot answer". I have a real good answer given to me from Dow Chemical that I will not post in the open forum.

If this topic is a little sensitive here, I understand and will let it go. This will probably get moved to AOP, but The biggest problem with using anything other than the proper media is; life expectancy, corrosion control, and organic growth control, not to mention efficiency and environmental responsibility.

You can use root beer if you wanted, does not mean you wont have any problems down the road. If a day goes by and you have learned nothing, I hope you got a lot of sleep. Originally Posted by GT Jets. I guess what really matters is why do you ask? Or are you just asking to ask?

glycol ground loop

Originally Posted by riderman. I agree and have to disagree with you. I admit this should be moved to You are correct and i feel I have been tought incorrect information. Carrier tought me about Methanol. I've learned about inhibited polyglycol, Ethelyne glycol, Ethenol, etc. One could state some types of blue wiindsheild fluid can be used as a anti freeze.How much can I save with geothermal?

See The Savings. There are two commonly used types of fluids that can be circulated through the ground loop system. The Standard Geothermal uses a mix of water, antifreeze Propylene Glycoland refrigerant. The fluid that circulates both inside the geothermal unit and throughout the copper ground loop is RA refrigerant often referred to as Freonwhich is environmentally safe.

This refrigerant happens to be the same refrigerant that circulates through the unit inside of your home for every water source geothermal manufactured today. This refrigerant is safe, non-toxic, and a non-flammable fluid.

The EPA has approved the refrigerant and copper ground loop to be safe and environmentally friendly to the earth see EPA Statements below compared to the conventional closed loop water geothermal system that uses antifreeze, which can be very harmful to our ground water. As a testament to its safety, think about your household refrigerator.

For more than 50 years a household refrigerator has been susceptible to spring a leak in the coil. If a leak were to happen, the refrigerant would leak into the freezer compartment where the food is being stored. It could take days or even months before you might realize that the refrigerator is getting warmer and has a leak. However, if the food was exposed to the refrigerant it can still be consumed without any harm to anyone.

Our geothermal system is innovative and state-of-the-art technology, that distributes heating and cooling when you need it, while saving you many dollars on energy, and saving the environment. Want more details? Contact us today, and our team of Geothermal Specialists can help you find the geothermal solution that works best for you!

Want to learn more about Geothermal energy and how it works? Our resource center has all the information you need! Toggle navigation. Geothermal Resource Center Want to learn more about Geothermal energy and how it works? Visit the resource center.Discussion in ' Maintenance and Troubleshooting ' started by josephparrisFeb 24, Log in or Sign up.

How to add water to a closed loop Discussion in ' Maintenance and Troubleshooting ' started by josephparrisFeb 24, What is the preferred method for adding some water to a closed loop system. I would assume due to expansion of pipe over a few months in a new system, that the loop would need to be topped off at some point and time, or do you wait for cavitation of the loop pump s? Is there a tool bicycle pump? What should the pressure of a closed loop be, if any?

Thanks in advance, J. Last edited: Feb 24, Is your unit equiped with PT ports? If so, easy peasy useing a garden hose and a needle adapter. If you have no PT ports, have them installed. Yes I do have PT ports. So, needle adapter and a garden hose. If this method is used I assume pressure is not a concern and do I let the pressure of the loop equalize with the pressure of my house water supply and all is well?

There really is not a set operating pressure. It just needs to circulate properly. Yes it is ok to boost the loop to whatever your domestic house pressure is within reason. Flow center products sell the needle adapters. Look at their pictures of the fill and pressure checkers to get a good idea of the concept, then buy the needle adapters and a trip to lowes or simmilar will get you the parts you need. I am familar with needles, I do have a temp probe for the PT port.

One more question, should the loop be filled while idle or with pumps running? Thanks for the caution of "purge the air from the hose"! I recently dealt with this to increase my glycol for better winter protection. I always hook up and let the loop pressure push into the sprayer before I pump it to ensure I push any air out of line. Thanks all, ordered the RAM-1 we will see how it works. I use a little electric pump. AMI ContractingMar 3, In Canada, where glycol is essential to protect HVAC systems from freezing, most contractors have a basic understanding of why glycol is used.

However, many may not realize all of the implications and issues that must be considered when the decision is made to use glycol in a system. Glycol in a hydronic system impacts the way that many circuit components such as pumps, pipes, air eliminators and boilers work.

glycol ground loop

If the wrong choices are made there can be serious consequences to the efficiency, performance and longevity of the system. Water is a better heat transfer media than glycol—you can see that when you compare the specific heat of the fluids. Compare this to 50 per cent glycol at 0.

The specific heat also changes with temperature and it only gets worse for glycol at lower temperatures. Glycol is also thicker and more viscous than water, making it more difficult to push through the pipes. If the system is originally designed for water, and then at the last minute changed over to glycol, you will most likely have problems as the initial sizing of components are no longer sufficient for the glycol system.

Related: What are the keys to optimal radiant system performance? Using the correct type and concentration of glycol is very important, as you only want to use as much as required to do the job. Too much glycol adds expense, impedes heat transfer, and affects pumping capacity.

Not enough glycol can lead to damaging and expensive freeze-ups. The type and concentration of glycol used is dependent on the project location and the type and specific requirements of the system. There are two basic types of glycols used in HVAC systems, propylene glycol and ethylene glycol. Both of these fluids have similar freeze protection and heat transfer characteristics with the main difference being that propylene glycol has a lower toxicity level.

Due to its lower toxicity, propylene glycol is more commonly used in residential and small commercial HVAC systems.

glycol ground loop

Figure 1 The percentage of glycol required to provide a certain level of protection against freezing or burst protection. Either type of glycol will always include added corrosion inhibitors to protect pipes and components.

There are many different types of inhibitors used that are specific to different applications. Using the correct type of glycol — inhibitor mix is crucial to providing long-term reliable system operation.


Climatic conditions are very different in Toronto and Yellowknife, so the levels of freeze protection required and the resulting concentration of glycol will vary for the same type of system installed in different locations. All glycol manufacturers provide charts see Figure 1which show the percentage of glycol required to provide a certain level of protection against freezing or burst protection.

However to provide pipe burst protection to the same temperatures, only 33 per cent glycol is required. Burst protection means that the fluid can no longer be pumped, but it has not expanded to a point where it will burst pipes. The HVAC applications that most commonly use glycol are snow and ice melting systems, ground source heat pumps, solar water heating systems, chilled water cooling systems, and in the hydronic systems that require pipe burst protection due to their location or activity level.

Some of these applications require high levels of freeze protection, while others only need a lower level of burst protection as a safety measure.

Snowmelt systems by their nature require a high level of freeze protection because all the components are located outside the building envelope and are exposed to the ambient conditions. This means that snowmelt systems require quite high levels of glycol concentration in the range of 50 to 60 per cent.

Solar water heating systems also require a very high level of freeze protection as solar collectors and piping are located outside the building.

Typically glycol concentration in the range of 45 to 60 per cent will be required, with most applications in Canada using 50 per cent glycol. Installations in the far north usually need to increase the concentration to account for colder winters. Solar systems also have the unique characteristic of producing very high fluid temperatures during summer stagnation conditions. This leads to very specialized glycol requirements that use special high temperature corrosion inhibitors to protect the fluid from breaking down rapidly.

Bookmark the permalink.

Responses to Glycol ground loop

Leave a Reply

Your email address will not be published. Required fields are marked *