Helical vs. Serpentine: What’s the Best Way to Build an Industrial Hot Oil Heater?

When it comes to designing industrial hot oil heaters, one question pops up time and again:
Should you choose a helical coil or a serpentine coil?

As longtime designers and manufacturers of high-performance thermal fluid systems, we know the answer makes a big difference in heater efficiency, longevity, and maintenance. Here’s a breakdown of both designs—and why Enerquip stands firmly behind the serpentine coil.

Helical Coil Heaters: Traditional but Less Efficient

Helical Coil HeaterThe helical coil design has been an industry standard for years. In this style, tightly wound coils are stacked within the radiant section of the heater (marked as A in the graphic), where heat transfers to the fluid through radiation on the inner surface of the tubes.

In the convection section (B), heat transfer occurs only on the outer surface, which limits overall efficiency.

Because of their tightly grouped coils, helical designs leave little room for thermal expansion. This can make repairs more difficult and lead to more frequent fluid degradation—especially at high temperatures. It’s not uncommon for stack temps to exceed 800°F, and the design typically limits operation above 400°F.

While widely used, this setup can become a maintenance headache over time.

Serpentine Coil Heaters: Enerquip’s Go-To Design

At Enerquip, we do things differently. Our standard hot oil heaters feature a serpentine coil design—and for good reason.

Enerquip Serpentine Coil Thermal Fluid Heater

In the radiant section (A), the spaced-out coils allow heat to reach the front, back, and sides of each tube. This improves heat transfer and reduces hot spots. In the convection section (B), more surface area is exposed, keeping stack temperatures lower and extending heater life.

This design not only improves thermal efficiency but also results in:

  • Less fluid degradation
  • Longer tube life
  • Simpler maintenance

That’s why we’ve made serpentine coil heaters the Enerquip standard—and why we encourage customers to consider this smarter, more efficient option.

Want to Learn More?

If you’re in the market for a new hot oil heater—or just doing your homework—here are some helpful resources to dig deeper:

Whether you’re replacing an old unit or planning your next system upgrade, our team is here to help you choose the right design—built to last and perform.

Call us at (833) 516-6888 or request a quote to get started.