The tub + "flat tank" assembly is *wrapped* with an insulation mat. Euro DW have no more the old exposed calrods since 15 years
Condensation drying is effective, provided rinse aid is used.
Machines are even quieter than a fridge. With the previous link of the countertop machine, look for Siemens dishwasher vids to have a clue : you'll hear just the noise of water splashing on the plastic foil.
Lab/surgery washers (e.g. SMEG and Miele) also use condensation drying. The incorporated condensor unit works with a separate feed/drain. I go crazy for this one in the vid, with a double glass door ... see it wash :