My dishwasher's design is focused on noise, so there is no air vent which would allow noise to escape. When the dishes are done, I always open the dishwasher to fully dry the still-hot dishes.
But, here's the quandary: do I open the door all the way, or just leave it cracked? It seems like the best approach would be to open the door all the way, in order to let as much air as possible flow past the moist dishes, thus quickly taking the water away. However, my instinct suggests that it might be better to only crack the door, so that entering dry air fully reaches equilibrium with the heat and moisture before leaving, thus better using the residual heat of the dishes to dry them.
Is there an analytical approach that would clearly promote either a cracked or a wide-open door?
Best Answer
You could use convection relationships and mass transfer to figure out exactly which scenario is better.
I don't really want to go through all that; because I'm quite sure fully opening will be a better option for several reasons.
Greater surface area between the inside and outside conditions. The greater this surface area, the more the damp air communicates with the dry air, and therefore the more vapour diffuses to the outside.
Better convection. When the dishwasher is only open a crack, the only place that the transfer takes place is at the top. Because the steam is less dense than air the steam will easily escape through that crack; but then air will have to come in to take it's place. This will lead to a limited flow rate of fresh air out, and cool air in. Either they will both only use a portion of the open surface area, or it will be a cyclic pattern of losing some steam, then filling back up (think of trying to empty a bottle too fast, air bubbles have to rush in and interrupt the flow).
If you open it fully, the less dense steam will want to rise to the top, while the cool air will go over the dishes and pick up more moisture and heat, before also rising.
There's also a chance that by leaving it only a crack open, it would increase the pressure in the dishwasher. That would make the vapourization less likely to occur. (I'll admit, this one is unlikely to do much. I assume the dishwasher has mechanisms so that it doesn't build up much pressure, even when fully closed, for safety reasons)