What this tool does
Connects measured baseline and proposed per-vehicle quantities to current local tariffs, annual operating cost and installed cost.
When to use it
Use after baseline and proposed water balances are documented; test low-throughput, high-cost and under-performance scenarios.
Inputs and supported units
Each labelled field explains the quantity it expects. Unit-system changes convert existing numeric entries once and keep calculations on a single SI internal basis. Supported shared units include L/min and GPM, metres and feet, kPa and psi, millimetres and inches, kW and hp, and °C and °F as relevant.
Calculation or decision method
Net annual savings = avoided water + avoided sewer − added annual operating cost
How to interpret the result
Read the primary result with the supporting breakdown and warning. A plausible number is not evidence that every input, operating case or design constraint has been included.
Worked example
Reducing fresh water from 180 to 72 L/vehicle at 120 vehicles/day and 300 days/year saves 3,888 m³/year before tariff and operating-cost effects.
Assumptions
Steady representative operating periods; user-entered meter, equipment, tariff and operating data; volumes are quantity balances rather than water-quality claims.
Limitations
No treatment technology, discharge route, oil-water separation, chemical compatibility, permit condition or manufacturer package is selected or approved.
Sources
- U.S. EPA WaterSense at Work — Vehicle Washes
- U.S. Department of Energy — Vehicle Wash Water-Use Estimating Methods
- International Carwash Association — Water Use, Evaporation and Carryout
- U.S. Department of Energy — Handbook of Water Use and Conservation