PROFESSIONAL DISHWASHER SIZING & WATER-TREATMENT SIMULATOR

Professional Dishwasher Sizing & Water-Treatment Simulator

Estimate professional dishwasher capacity, daily workload, water consumption, water-softener service intervals and preventive maintenance requirements. This interactive calculator supports preliminary equipment selection for restaurants, cafés, hotels, canteens and institutional kitchens.

How to use: enter the number of covers served, loads per cover, rated loading capacity, programme duration, water consumption and measured water hardness. The simulator estimates throughput, water demand and a preliminary treatment-service interval. Select optional equipment modules to generate a preliminary recommendation.

1. Kitchen demand and operating profile

Application Café / bar Restaurant Hotel / buffet Canteen / institutional kitchen Healthcare / care facility Covers served per day Rack-equivalent loads per cover

Adjust this assumption to the actual number of dishwasher loads generated per customer. It is not a universal industry constant.

Place settings or equivalent items per cycle

Use the manufacturer's definition of rated capacity. A rack, basket, flight and individual place setting are not interchangeable units.

Operating hours per day Peak-load factor 1.0 — evenly distributed 1.25 — moderate peak 1.5 — strong peak 2.0 — highly concentrated peak Programme cycle time (minutes)

Enter the actual programme duration from the technical data sheet. The example value is not a specification for every machine.

2. Equipment and water consumption

Equipment family Undercounter / glasswasher Hood-type / pass-through Rack conveyor Flight-type conveyor Fresh water per cycle (litres) Water input definition Total fresh water per machine cycle Litres per rack-equivalent load Additional daily water consumption (litres)

Include manual pre-rinsing, cleaning, connected equipment and other relevant water uses. Avoid double-counting water already included in the manufacturer's consumption figure.

Operating days per year Water cost per m³ (your currency)

Conveyor equipment is often specified in racks per hour or litres per rack. For these machines, use the manufacturer's rated throughput and consumption basis rather than assuming a batch-machine cycle definition.

3. Water hardness and water treatment

Measured inlet-water hardness Hardness unit French degrees (°fH) German degrees (°dH) mg/L as CaCO₃ (ppm) Target residual hardness (mg/L as CaCO₃) Usable exchange-capacity rating (m³ × °dH)

Enter the capacity rating provided by the water-treatment supplier. Do not estimate exchange capacity from resin volume alone.

Resin volume (litres, reference only) Salt used per regeneration (kg) Filter cartridge rated service capacity (m³) Treatment configuration Ion-exchange water softener / resin Replaceable filter cartridge Reverse osmosis (RO) No treatment / unknown

Conversions: 1 °fH = 10 mg/L as CaCO₃; 1 °dH ≈ 17.848 mg/L as CaCO₃; 1 °dH ≈ 1.7848 °fH. Use a recent water analysis. Hardness removal, salt consumption and regeneration intervals depend on the specific system and its operating settings.

4. Equipment selection and optional modules

Available dishwashing staff 1 operator 2 operators 3 or more operators Soil level and operating intensity Standard Heavy soil / frequent peak loads High hygiene requirements

Integrated or external water softener Reverse-osmosis module / final-rinse polishing Automatic detergent and rinse-aid dosing Heat recovery / energy-saving module Drain heat recovery / drain pump, if required Connectivity / remote monitoring Wash-tank filtration / soil separation

Confirm compatibility, water pressure and flow, drainage, electrical supply, ventilation, installation clearance, rack dimensions and local hygiene requirements with the manufacturer and installer.

Estimated results

Estimated cycles per day—

Required peak throughput—

Theoretical cycle capacity per hour—

Estimated daily water—

Estimated annual water—

Estimated annual water cost—

Hardness as CaCO₃—

Approximate treated volume to service—

Estimated service interval—

5. Preventive maintenance checklist

Adapt frequencies to the equipment manual, water quality, running hours, hygiene plan and service contract. Electrical isolation and applicable safety procedures must be followed before technical work.

Operator — daily / each shift

Remove food debris and clean tank filters and strainers as instructed. Check wash and rinse arms for blockages; clean removable parts according to the manual. Check detergent and rinse-aid containers, tubing and dosing indicators. Inspect for leaks, abnormal noise, error messages and poor washing results. Run the prescribed end-of-day cleaning routine and leave the machine in the recommended state. Check water-softener salt and status, if applicable; use the specified salt and procedure. Record unusual results, alarms and maintenance actions in the site log.

Operator — weekly, or as instructed

Inspect curtains, seals, doors, baskets, racks and accessible spray nozzles. Clean external surfaces and accessible scale or soil deposits with approved products. Review chemical use, washing results, water consumption and alarms. Check the visible condition of hoses and connections without dismantling safety-critical components.

Qualified technician — planned service

Verify wash and rinse temperatures, programme parameters, pressure, flow and final-rinse performance against the manual. Check dosing calibration, chemical tubing, non-return devices and detergent/rinse-aid consumption. Inspect pumps, seals, valves, heaters, thermostats, door interlocks, electrical connections and safety devices. Inspect scale build-up, water treatment, regeneration settings and residual hardness downstream of the softener. Check cartridge service indicators and differential pressure where applicable; replace cartridges at the manufacturer's limit. For RO systems, review feed-water conditions, permeate flow and conductivity, reject flow, prefilters and membrane-cleaning criteria. Document readings, parts, corrective actions, next due date and water-quality test results.

6. Water-treatment calculation guide

Parameter	Calculation / rule	Important limitation
French hardness	°fH × 10 = mg/L as CaCO₃	Use measured inlet-water hardness.
German hardness	°dH × 17.848 = mg/L as CaCO₃	Confirm the unit used in the supplier's capacity rating.
Daily water consumption	Estimated machine water + additional daily water	Do not double-count manual pre-rinsing or connected equipment.
Resin regeneration	Indicative treated volume ≈ exchange-capacity rating (m³ × °dH) ÷ hardness removed (°dH)	This is a simplified estimate, not a universal resin specification.
Cartridge replacement	Use the exact cartridge capacity, service indicator or supplier-defined quality limit.	Sediment and carbon cartridges do not necessarily remove hardness.
Reverse osmosis	Monitor permeate conductivity, flow, pressure and supplier-defined limits.	Membrane life cannot be predicted from hardness alone.

Important: this simulator assumes that the entered daily water consumption passes through the selected treatment system when estimating the service interval. If only part of the water is treated, or several appliances share the same softener, use the actual treated-water volume. The estimate must not be treated as a certified regeneration or filter-replacement schedule.

Disclaimer and scope of use

This calculator is provided for educational purposes, preliminary planning and equipment-selection support only. It is not a substitute for a professional site survey, laboratory water analysis, a validated hygiene risk assessment, applicable regulations or the installation, operation and maintenance manuals issued by the dishwasher and water-treatment manufacturers.

All outputs depend on user-entered assumptions and simplified calculations. Actual throughput, water and energy consumption, chemical dosage, water-softener capacity, regeneration frequency, cartridge life and reverse-osmosis performance vary with the exact model, loading pattern, inlet-water quality, flow and pressure, temperature, operating conditions and maintenance history.

Do not use the calculated interval as the sole basis for replacing a filter or scheduling regeneration. Follow the supplier's ratings, control settings and service indicators, and verify water quality with suitable tests. Final equipment and module selection must be confirmed by the manufacturer or an appropriately qualified installer or technician.

The author accepts no liability for purchasing, operating, maintenance, hygiene or compliance decisions made solely from this estimate. No manufacturer endorsement is implied.

Author

Ryan KHOUJA — International B2B Sales, Export Management and Technical Business Development.

This independent technical-information resource is intended to support informed discussion between kitchen operators, distributors, installers and professional-equipment manufacturers.