Every dishwasher will have the standard spray arm technique for cleaning your dishes. This is a simple mechanism where water is drawn into the arms (one on the bottom level, one underneath you top level) and the pressure forces them to spin. Each arm has a number of spouts through which the water is forced and the different spin patterns wash the contents of the unit.
Upper Spray Arms
You might find with some models that they come with an additional third spray arm in the roof of your dishwasher. This is a smaller arm which sprays down onto the top tray of items and assists in washing items from above. Not all manufacturers have this third arm so if you’re keen on cleaning a dishwasher full to the brim it might be worth considering.
Satellite Spray Arms
Do you have lots of awkwardly shaped items you wash regularly? If so, ordinary spray arms might not be able to wash your items very well, leaving blind spots in terms of where the spray arms can reach. To combat this, some manufacturers have introduced an extra, tiny arm at the apex of the large arm which rotates itself and simply provides extra coverage within the original spinning circle as it goes.
Waterwall™ Jet Spray
Introduced by Samsung, this is a revolutionary new dishwasher, with a different take on the spray arm. With three different arms, the machine produces jets of water – wall to wall – to provide a quicker, more thorough clean. Other manufacturers are now catching on to idea of using something other than a rotating arm, but these are highend models so you’ll need to consider your budget before making a purchase.