Indirect Heat Exchanger Tank Coils: Compare Convoluted Coil (Wave Coil) to Standard Coil
Indirect domestic water heating tanks are used with boilers, hydronic heat pumps, and solar water heating, and generally use a smooth wall coil. The Chiltrix DWH40, DHW80 and DHW105 indirect tanks use a convoluted coil.
The image below (taken in our tank manufacturing facility) shows the convoluted coil material. Note the wave effect on the Chiltrix coil wall.
The convoluted coil design provides more heat transfer surface contact area per inch and creates increased turbulence that disrupts laminar flow in the heat transfer fluid. This delivers enhanced thermal performance and faster water heating. The high thermal conductivity (K value of 16 W/m·K) of the 2205 stainless steel adds even more improvement compared to a standard stainless steel coil.
A convoluted coil adds around 50% to the total heat transfer surface area.
Below is an image of standard indirect water heating coils. Note the smooth wall of the standard coil.
Why the Chiltrix Convoluted Coil Performs Better:
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- Up to 50% more surface area
- Increased turbulence for better heat transfer
- Larger diameter (1.25″) and longer length (72′ on DHW80)
- Transfers heat up to 5× faster than a standard indirect tank coil
- Made from ultra-high-grade 2205 Duplex stainless steel (far stronger and more corrosion-resistant than 316L or 304)
The Chiltrix coil also part of how and why Chiltrix holds the #1 highest performance rating among all certified tanks (U.S. Department of Energy).
Product Documentation, Specs, and Certifications
About Chiltrix Indirect Water Heating Tanks
DHW80 Spec SheetAll Chiltrix DHW Tanks Have Oversized Coils For Faster Heat Transfer
The DHW40, DHW80, and DHW105 inner tanks are made from ultra-high grade 2205 DUPLEX stainless steel.
Duplex stainless steel is far stronger, and has far better resistance to corrosion or water quality problems as compared to normal stainless steel such as 316L or 304 stainless.
The larger diameter (1.25″), longer than normal (33′ for DHW40, 66′ for DHW80 and an amazing 196′ for DHW105), convoluted coil transfers heat up to up 5x faster than a standard indirect tank coil configuration for faster recovery.
