Dishwasher - Commercial Dishwashers

Commercial Dishwashers

Large heavy-duty dishwashers are available for use in commercial establishments (e.g. hotels, restaurants) where a large number of dishes must be cleaned.

Unlike a home dishwasher, commercial dishwashers do not utilize a drying cycle (commercial drying is achieved by heated ware meeting open air once the wash/rinse/sanitation cycles have been completed) and thus are significantly faster than their residential counterparts. Washing is conducted with 65-71 C / 150-160 F temperatures and sanitation is achieved by either the use of a booster heater that will provide the machine 82 C / 180 F "final rinse" temperature or through the use of a chemical sanitizer. This distinction labels the machines as either "high-temp" or "low-temp".

Some commercial dishwashers work similar to a commercial car wash, with a pulley system that pulls the rack through a small chamber (Known widely as a "rack conveyor" systems). Single-rack washers require an operator to push the rack into the washer, close the doors, start the cycle, and then open the doors to pull out the cleaned rack, possibly through a second opening into an unloading area.

In the UK, the British Standards Institution set standards for dishwashers. In the US, the NSF International (an independent not-for-profit organization) sets the standards for wash and rinse time along with minimum water temperature for chemical or hot water sanitizing methods. There are many types of commercial dishwashers including under counter, single tank, conveyor, flight type, and carousel machines.

Commercial dishwashers often have significantly different plumbing and operations than a home unit, in that there are often separate spray arms for washing and rinsing/sanitizing. The wash water is heated with an in-tank electric heat element and mixed with a cleaning solution, and is used repeatedly from one load to the next. The wash tank usually has a large strainer basket to collect food debris, and the strainer may not be emptied until the end of the day's kitchen operations.

Water used for rinsing and sanitizing is typically delivered directly from building water supply, and is not reused. The used rinse water falls into the wash tank reservoir, which dilutes some of the used wash water and causes a small amount to drain out through an overflow tube. The system may first rinse with pure water only, and then sanitize with an additive solution that is left on the dishes as they leave the washer to dry.

Additional soap is periodically added to the main wash water tank, from either large soap concentrate tanks or dissolved from a large solid soap block, to maintain wash water cleaning effectiveness.