The water factor (WF) is calculated by dividing the total weighted per-cycle water consumption (Q) by the capacity of the clothes washer (C). The resulting value indicates the water efficiency of the washing machine; the lower the number, the more water-efficient the washer is.
Here's a more detailed explanation:
Understanding Water Factor (WF)
The water factor is a metric used to measure the water efficiency of clothes washers. It's a simple ratio that provides a standardized way to compare the water usage of different models. A lower water factor signifies better water efficiency, indicating that the washer uses less water per pound of laundry.
The Formula:
The formula for calculating water factor is:
WF = Q / C
Where:
- WF = Water Factor (gallons per cycle per cubic foot)
- Q = Total weighted per-cycle water consumption (gallons)
- C = Capacity of the clothes washer (cubic feet)
Breaking Down the Components:
-
Total Weighted Per-Cycle Water Consumption (Q): This is the total amount of water the washing machine uses during a typical wash cycle. The weighting often considers different cycle settings (e.g., normal, delicate, heavy-duty) and their frequency of use to reflect real-world washing habits. Test procedures dictate how this value is determined and what cycles are used in its calculation.
-
Capacity of the Clothes Washer (C): This represents the volume of clothes the washing machine can hold, typically measured in cubic feet. This is the drum volume.
Example Calculation:
Let's say a washing machine uses 10 gallons of water per cycle (Q = 10 gallons) and has a capacity of 2 cubic feet (C = 2 cubic feet).
The water factor would be:
WF = 10 gallons / 2 cubic feet = 5 gallons per cycle per cubic foot
Interpreting the Water Factor:
In this example, the water factor is 5. This means that the washing machine uses 5 gallons of water for every cubic foot of clothes washed in a cycle.
Significance of Water Factor:
- Water Conservation: Choosing a washing machine with a lower water factor helps conserve water.
- Energy Savings: Water efficiency often translates to energy savings because less hot water needs to be heated.
- Cost Savings: Lower water and energy consumption leads to lower utility bills.
- Environmental Impact: Reduced water and energy usage minimizes the environmental footprint.
Where to Find Water Factor Information:
- EnergyGuide Label: Look for the EnergyGuide label on new washing machines. This label provides information about the appliance's energy and water consumption, including the water factor.
- Manufacturer Specifications: Check the manufacturer's website or product manual for detailed specifications, including the water factor.
- Energy Star Website: The Energy Star website provides a list of certified energy-efficient appliances, including washing machines, along with their water factor ratings.
