Page 122 - WaterSense at Work

October 2012
Wok Stoves
Wok Stove Replacement
During the course of a 12-hour day, a conventional water-cooled wok stove can use
more than 700 gallons of water. Switching to a waterless wok or one that uses recir-
culated chilled water can eliminate this use of single-pass cooling water. To estimate
facility-specific water savings and payback, use the following information.
Water Use and Savings
To estimate the water used for cooling of a conventional wok stove and subsequent
water savings associated with a waterless wok stove or one that uses recirculated
chilled water, identify the following information and use Equation 4-11:
Flow rate of the cooling water. This flow rate is typically 1.0 gpm.
Average daily use time.
Days of facility operation per year.
Equation 4-11. Water Use and Savings FromWater-CooledWok Stove Replacement
gallons per year)
= Current Wok Stove CoolingWater Flow Rate x Daily Use Time x Days of
Facility Operation
Current Wok Stove Cooling Water Flow Rate (gallons per minute)
Daily Use Time (minutes per day)
Days of Facility Operation (days per year)
To calculate the simple payback from the water savings associated with replacing an exis-
ting conventional wok stove, consider the equipment and installation cost of the replace-
ment waterless wok stove or one that uses recirculated chilled water, the water savings as
calculated using Equation 4-11, and the facility-specific cost of water and wastewater.
The facility should also consider the energy impact of replacing old equipment.
Waterless wok stoves can use about 2 percent more energy than a conventional wok
but they use at least 90 percent less water.
Additional Resources
Alliance for Water Efficiency. Waterless Wok Introduction.
City West Water Limited. Programs and Assistance, Woking the Way to Water Savings.
op. cit.