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.

• 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.

• 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.