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.

Below shows an image from our tank manufacturing facility showing the convoluted coil material. Note the wave effect of the Chiltrix coil wall. The convoluted coil design provides more heat transfer surface contact area per inch and increased turbulence in the heat transfer fluid, providing enhanced thermal performance and faster water heating. The high K value (16 W/m*K) of the 2205 stainless offers even further thermal improvement compared to a standard stainless steel coil.

A convoluted coil adds around 50% to the total heat transfer surface area.

Indiect water heat tank manufacturer chiltrix factory, pic shows convoluted indirect coils
2205 Stainless Indirect Tank Coil

Below shows an image of standard indirect water heating coils. Note the smooth wall of the standard coil.

Image show standard indirect tank coil at Chiltrix tank manufacturering facility

316L Stainless Steel Standard Coil

More info on Chiltrix indirect water heating tanks

See indirect coil information

See spec sheet

See pics of DHW80 stainless solar hot water / indirect coil tank

See Chiltrix tank manual

The DHW80 inner tank and convoluted coil is 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 (72'), convoluted coil transfers heat up to 2x faster than a standard indirect tank coil configuration.

Below: Picture of convoluted coil used in manufacturing Chiltrix DHW80 indirect tanks.

close-up image of concoluted indirect tank coil