actually, having grown up with them, I can attest they're called swamp coolers because on buildings they were used with a steady flow of fresh water over the excelsior pads, the unevaporated water running out a drain hose onto the ground nearby, which resulted in a swamp next to the house
they only really produce 'humid conditions' inside when ambient humidity is already too high for them to do any cooling
eventually someone got the bright idea of making a model with a circ pump so there wasn't so much water wasted, which model of course cost twice as much, so my family never had one
Bill
