Have you been following our Made in Mitchell blog post series? Join us on our virtual tour of our manufacturing facility to get an exclusive behind the scenes look at where we make our award-winning geothermal systems—all from the comfort of your own browser! We’ve already taken a look at our sheet metal bending procedure; so for the next stop on the tour, let’s check out the coaxial heat exchanger assembly process

Before we begin, let’s do a quick review of what exactly the coax is. It is essentially a tube inside of a tube. Fluid from the ground loop system passes through an internal copper tube while refrigerant passes through a surrounding tube. This process transfers the heat energy from one fluid to the other due to the temperature difference between them. 

So why do we foam in the coax? Our process protects against moisture and improves unit performance and reliability! 

The coaxes come to our facility without any insulating foam on them. After they arrive, the coaxial heat exchangers go to the foaming station. For many models like water-to-water and horizontal units, the coaxes are wrapped in foam tape before going to the assembly line to be installed in a geothermal system. 

When Enertech introduced the revolutionary XT multi-position vertical packaged models in 2010, the units featured an equally innovative solution to insulating the coaxial heat exchanger. Our design engineers proposed encasing the coax inside an expanded polystyrene (EPS) clamshell, which was then filled with foam to eliminate air pockets and enhance the overall insulating qualities. The idea worked, and the XT models saw a boost in performance and efficiency over previous generation equipment. 

As research and development of our new YT multi-positional vertical packaged and VS/VT compact vertical models began our team investigated ways to make the foaming process more reliable, reduce the risk of corrosion and rust, and increase the overall efficiency of the unit. That led to the creation of a new process where we encase the coax in a coating of high-density foam to create an airtight seal around it. This eliminates the potential for condensation or “sweat” to develop on the outside of the coax, reducing the risk of corrosion and rust as the unit ages. It also increases the efficiency of the unit because the process is more reliable and the spray foam has a better R-value per inch than previous methods.  

Enertech engineers and manufacturing personnel spent months developing and perfecting this new process, and Enertech invested in the tools to do the job right. Mitchell team members went through highly specialized training with the manufacturer of the spray foam equipment to ensure that the final product would be perfect every time. 

After the spray foam has been applied, the coax is taken to a secondary station where it gets cleaned and inspected. This ensures that every geothermal system meets Enertech’s high standard of quality. During the next stage of the process, the water fittings are soldered in place and the coax is ready for installation into the geothermal cabinet. 

Once the remaining internal components are added, each unit goes through a rigorous quality-testing phase to insure all performance parameters are met. Units are then shipped and installed, providing years of reliable, efficient comfort. 

Every employee at Enertech takes pride in the equipment we build. That comes from our dedication to quality, craftsmanship, and innovation. In developing new products and technologies, we rely on the valuable collaboration of our dealer and distributor partners, and our talented employees, all working together. That’s how Enertech is making geothermal better!


Don’t forget to visit us on the Enerstate again for the next stops on our virtual tour of the Enertech manufacturing facility.