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DHW Volume per Use

What this tool does

Electric storage water heater.
Electric storage water heater. (Source: U.S. Department of Energy)

This tool determines the volume of hot water used given an amount of mixed (hot + cold) water used and the temperatures of the hot, cold, and mixed water. The amount of mixed water can be specified by volume directly, or from a flow rate and duration.

Calculated values

  • Hot water used in gallons or liters.
  • Mixed water volume.
  • Percentage of hot water and cold water (displayed in the additive bar chart).
  • Hot water flow rate.

Tips

  • Clicking the label for any input or result will cause a popup help box to appear. This help box includes the allowed and normal values (for inputs).
  • The amount of mixed water can be specified by volume directly, or from a flow rate and duration. Specify the method using the drop-down selector.
  • The hot water temperature entered in the tool must be greater than the cold water temperature.
  • The “Mixed water temperature” entered must be between the hot and cold water temperatures.
  • The percentage of hot water and cold water for the volume of water is displayed as an additive bar chart under the “Mixed water temperature” input.

Disclaimer

This content is a work created with funding provided by the United States Department of Energy under Contract no DE-AC05-076RL01830 for the operation of Pacific Northwest National Laboratory. The information and guidance provided by Pacific Northwest National Laboratory (PNNL) in the content are intended solely for educational purposes only and do not constitute formal training or certification. It is provided with the explicit understanding that neither the United States Government nor the United States Department of Energy, nor the Contractor, nor any or their employees, nor any jurisdiction or organization that has cooperated in the development of these materials, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness or any information, apparatus, product, software, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Viewers assumes full responsibility for all actions that they may take from information provided in this content including ensuring the safety, code compliance, and proper functionality of any products they choose to install. Installation and use of such products should be performed in accordance with local regulations and manufacturer instructions.