Commercial Dishwasher Buying Guide Australia: Underbench vs Passthrough vs Conveyor

Start with dirty returns, not the catalogue

A dishwasher does not operate in isolation. Map the path from the customer or production area:

1. Dirty items arrive.
2. Food waste is scraped and separated.
3. Items are sorted into the correct racks.
4. Heavy soil is pre-rinsed where required.
5. The rack enters the machine.
6. Clean items leave the machine without crossing dirty flow.
7. Items air-dry and return to clean storage.

Count the racks generated in the busiest 15- or 30-minute return period. Include plates, bowls, cups, cutlery, trays, containers and kitchen utensils. A venue that seats 80 people across a relaxed service has a different requirement from an 80-seat function room that clears every table at once.

A planning calculation for peak racks

Use a physical rack test wherever possible. For early planning:

Peak racks required = items returned in the peak period ÷ verified items per rack

Then add:

• separate rack types that cannot be combined;
• rewash allowance based on the real soil profile;
• staff loading/unloading time;
• machine recovery and any heat-up delay;
• rack travel and storage;
• a sensible operational buffer.

Do not divide total daily items by trading hours. That average hides the peak that causes wash-up to fail.

Underbench commercial dishwashers

An underbench machine loads from the front and normally processes one rack per cycle. It fits beneath or beside a bench and can work well where floor area, budget and rack volume are limited.

Best suited to

• small cafés and restaurants with manageable return peaks;
• bars using a dedicated glasswasher plus a separate dish machine;
• satellite kitchens and staff dining areas;
• venues where the same operator can scrape, load and unload without blocking another task.

Advantages

• compact footprint;
• lower initial project complexity than larger systems in many sites;
• straightforward rack-based operation;
• can be positioned close to a small return point.

Watch-outs

• repeated bending and door clearance;
• limited landing space;
• clean racks can collide with dirty returns;
• a short cycle time does not guarantee the operator can maintain that rate;
• larger trays, pots and utensils may not fit;
• heat and steam still need to be managed.

Compare ProChef’s underbench dishwashers only after checking rack size, usable opening height, connection requirements and the manufacturer’s sanitising program.

Passthrough or hood-type dishwashers

A passthrough machine accepts a rack on a bench, lowers a hood over the rack and allows the clean rack to exit onto another bench. A well-designed L-shaped or straight system creates a visible dirty-to-clean direction.

Best suited to

• busy restaurants, pubs, clubs and function venues;
• operations with sustained rack flow;
• kitchens where separate inlet and outlet benches can be installed;
• venues that need a more ergonomic loading height.

Advantages

• faster physical rack movement than repeated front loading;
• clear opportunity to separate dirty and clean sides;
• generous pre-rinse and sorting area can be integrated;
• operator does not repeatedly bend to floor-level racks.

Watch-outs

• requires more floor and bench space;
• hood opening height and ceiling/services must be checked;
• pre-rinse, drainage and ventilation must be coordinated;
• corner installations need the correct bench and machine orientation;
• stated cycles still depend on operator pace and heat recovery.

Browse passthrough dishwashers and involve ProChef’s kitchen design team when the wash area and return route need to be coordinated.

Conveyor dishwashers

Conveyor systems move racks or wares continuously through wash and rinse stages. They are intended for high, sustained throughput rather than occasional surges followed by long idle periods.

Best suited to

• large hotels, hospitals, aged-care, education and production kitchens;
• high-volume functions and institutional dining;
• operations with enough staff and space to feed, unload and sort continuously;
• sites with utilities and ventilation designed for the system.

Advantages

• continuous high-volume processing;
• workflow can be engineered around defined loading and unloading roles;
• suitable for long service periods with predictable return streams.

Watch-outs

• high space and infrastructure demand;
• an undersized sorting or unloading area can constrain the entire line;
• labour must be planned at both ends;
• utilities, ventilation, noise and service access require early coordination;
• low utilisation may make the system poor value.

Review conveyor dishwashers against a documented peak return model and complete site services.

Side-by-side comparison

This table is a selection framework, not a capacity promise. Verify exact models and site conditions.

Dishwasher or glasswasher?

Glassware has different priorities: rack design, water quality, chemical settings, cycle, drying and the need to protect presentation. A busy bar may need a dedicated glasswasher even when the kitchen has adequate dishwashing capacity.

Do not assume one machine can handle every item well. Map simultaneous glass and plate returns, especially at functions.

Rack format and usable capacity

The rack is the unit of throughput. Before choosing a machine:

• test your largest plate, tray and utensil;
• count actual pieces per rack without nesting or blocking spray;
• identify separate plate, cup, cutlery and glass racks;
• confirm rack dimensions across the proposed system;
• allow enough spare racks to stage dirty, washing, drying and clean items.

Explore compatible dishwasher racks, but confirm model compatibility before ordering.

Water, drainage, electricity and ventilation

For every shortlisted model, record:

• water pressure, temperature and connection requirements;
• water hardness and recommended treatment;
• drainage height, flow and pump/gravity arrangement;
• voltage, phase, current or connected load;
• plug type or hardwired connection;
• heat and steam released into the room;
• detergent and rinse-aid dosing;
• machine and service clearances.

Have the relevant licensed trades confirm the existing site before purchase. A machine with the right rack capacity can still be unsuitable if the supply, drain or electrical capacity cannot support it.

Cleaning and sanitising are separate outcomes

FSANZ explains that cleaning removes dirt, grease and food waste, while sanitising destroys microorganisms. Items must be cleaned before they can be effectively sanitised. FSANZ advises operators to follow manufacturer instructions, scrape or rinse excess food, load items so water reaches all surfaces, use the program designed for sanitation, confirm items are clean and dry, and clean and service filters and the machine regularly.

Read FSANZ cleaning and sanitising guidance. Do not publish a universal rinse-temperature claim for all machines; the correct validated program depends on the equipment and sanitising method.

Water treatment and lifetime cost

Water treatment can affect wash results, scale, glass presentation, detergent use and component life. Ask for a water assessment where required and include filters, cartridges, salt or treatment servicing in the operating budget.

Compare:

• purchase price;
• freight, benches and installation;
• water and energy per relevant cycle or rack;
• chemical consumption;
• water-treatment consumables;
• labour at the wash station;
• scheduled service and parts support;
• cost of downtime or rewash.

Use comparable manufacturer data and your actual tariffs. Do not convert a marketing percentage into a guaranteed saving.

Site-readiness checklist

• Peak racks calculated from real ware and return patterns.
• Largest items physically fit.
• Dirty and clean routes do not cross.
• Scrape, sort and pre-rinse space is adequate.
• Clean landing and air-drying space is adequate.
• Water, drainage and electrical requirements verified.
• Water treatment specified.
• Chemicals and dosing included.
• Steam, heat, noise and ventilation considered.
• Delivery path and doorway dimensions checked.
• Cleaning and service access protected.
• Staff training and shutdown routines planned.

Frequently asked questions

How many racks per hour do I need?

Calculate racks during the busiest return period using your actual ware mix. Add workflow time and a justified buffer. Do not size from daily totals or headline cycle time alone.

Is a passthrough dishwasher always faster than an underbench model?

It usually supports a more efficient physical flow, but actual throughput depends on the exact machines, programs, recovery, soil, operator, racks and layout. Compare verified operating conditions.

Do I need a dishwasher and glasswasher?

Potentially. If glass and plate peaks overlap, or glass quality requires a dedicated process, separate machines can reduce contention. Model both return streams.

Can a commercial dishwasher replace manual sanitising?

A suitable dishwasher can clean and sanitise when correctly selected, installed, maintained and operated on the manufacturer-specified program. The business remains responsible for verifying its process.

Choose the wash system, not only the machine

The correct dishwasher is the centre of a complete wash area: returns, scraping, racks, water, chemicals, staff, drying and clean storage. Design the flow first, then select the machine that can sustain it.

Explore ProChef’s warewashing equipment or request a quote with your rack estimate, site details and largest wash items.

General information only. Confirm food-safety procedures, model performance, utilities and installation with the manufacturer, relevant authorities and qualified trades.

Sources

• Cleaning and sanitising — FSANZ
• Safe Food Australia — FSANZ