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Hybrid Water Heaters

The patent pending Sioux Hybrid Water Heater maximizes the benefits of coil and direct-fired technologies to achieve 98% true efficiency.

Hybrid Heater



Benefits of the Sioux Hybrid Water Heater
  • Produces 98% efficiency.
  • Achieves 200°F (93°C) outlet temperature.
  • Provides recirculation mode, as required to maintain water storage tank temperature.
  • Media section provides exceptionally high overall efficiency.
  • Coil section allows the heater to reach high temperature without producing steam.
  • Ships complete. No assembly required.
  • Third party approved to UL508A and CAN/CSA-C22.2 No. 14-10, ensuring that the entire control panel assembly meets the UL and CSA standards. Canadian Registration Number (CRN).


Myths of Direct-Fired Water Heaters
  • 99.9% efficiency.
  • Can recirculate from a storage tank.
  • Efficiency can be measure by exhaust gas temperature.
  • Storage tanks are unnecessary because peak demands can be met with a larger heater.
  • Do not require ASME Stamp.


The Truth about Direct-Fired Water Heaters and Why the Sioux Hybrid Heater is Superior
  • Stack temperature does NOT provide an accurate measure of combustion efficiency. EFFICIENCY = Energy out/ Energy in:
    This data is difficult to measure: energy content of fuel used, fuel consumption, water temperature and flow, combustion air temperature and flow, electrical consumption, and other variable which are difficult to measure. Imagine this: If only 50% of the fuel was burned (for example from water drops contacting fuel prior to combustion), stack temperature would be low, but efficiency would be terrible...Therefore low stack temperature does not mean high efficiency.
                 * The SIOUX Hybrid Heater has been designed as a high efficiency system, which operates above 95% efficiency.

  • At what discharge temperature is efficiency measured? Heater efficiency should be measured at the typical operating temperature for your plant, which for most ready mix customers, is 160°F (71°C) to 180°F (82°C). Direct fired units measure efficiency well below that temperature. Typical direct fired heater efficiency is much lower at the temperature required, due to heating water into steam, which escapes out the exhaust.
                 * The SIOUX Hybrid Heater's coil section of the design eliminates this problem because high temperatures are reached within the coil section where the water cannot escape as steam, so you can heat water to much higher temperatures, and maintain exceptional efficiency.

  • What is efficiency during recirculation (needed to maintain your water storage tank temperature)? With a typical direct fired unit operating in recirculation mode (where tank water is pumped through the heater to maintain tank temperature), the heater water discharge temperature soars well above the design limit, thereby discharging excessive steam to the atmosphere, resulting in totally unacceptable efficiency, so direct fired heaters are not used for recirculation.
                * The SIOUX Hybrid Heater has been designed specifically to recirculate to a water storage tank and maintain high efficiency. The ability heat water to 208°F (93°C), and the use of a modulating burner make the Hybrid design ideal for maintaining tank water temperature.

View the Hybrid Heater Brochure


Getting Into Hot Water- Concrete InFocus Article Featuring the Hybrid Water Heater


Click here for engineering drawing


To compare the Hybrid Heater to Sioux's other water heating systems click here.


To see what energy rebates are available in your state click here