not so exaggerating la..2-3 litres a day...haha...i only top up 500ml to one litre a day for my 2ft, the most with my cooling fans spinning 24 x 7 mode...unless you are talking about living room fans like TDK mount on top.
the only prob with using cooling fans is that, the lowest temp it can go is 27 and most of the time is 28-29 and you have to replace them once they become inefficient or rusty.
yes, sensitive fishes + corals and rare fishes + corals will be a big risk...can only keep hardy fishes like damsels, common clowns, blennies...
if you ask me will i get a chiller?..i say, yes. Our weather is too humid and warm.