Basic HTML Version

4-54

October 2012

Water Use After Retrofit

To estimate the water use after retrofitting an existing wash-down sprayer with a

nozzle, use Equation 4-24, substituting the flow rate of the retrofit nozzle. Self-closing

nozzles often flow at a rate of 7.0 gpm.

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Water Savings

To calculate the water savings that can be achieved from retrofitting an existing

wash-down sprayer with a nozzle, identify the following information and use Equa-

tion 4-25:

••

Current water use as calculated using Equation 4-24.

••

Water use after retrofit as calculated using Equation 4-24.

Where:

••

Current Water Use of Wash-Down Sprayer (gallons per year)

••

Water Use After Retrofit or Replacement (gallons per year)

Payback

To calculate the simple payback from the water savings associated with the wash-

down sprayer retrofit, consider the equipment and installation cost of the retrofit

self-closing nozzle, the water savings as calculated using Equation 4-25, and the

facility-specific cost of water and wastewater. Self-closing nozzles typically cost $100.

A pressure washer or water broom typically uses 2.0 gpm, while heavy-duty hoses

can deliver higher flow rates from 9.0 to 20.0 gpm.

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Current Water Use

To estimate the current water use of an existing wash-down sprayer, use Equation

4-24.

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FSTC,

op. cit.

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EPA and DOE’s ENERGY STAR,

op. cit.