As explained in Why does water evaporate spontaneously at room temperature despite ΔG > 0? water evaporates in room temperature because partial pressure of water is less than "standard" conditions of air in normal atmosphere.
If I need to evaporate or boil 100 g of water to artificially increase humidity of air over time, does it make any difference in total energy comsuption if I slowly evaporate the water or if I boil it rapidly? Common sense seems to indicate that rapidly boiling the water takes much more energy but is it really so? I would not be surprised if slowly evaporating the water would take exactly the same amount of energy (which would cause slight temperature drop in room temperature) but I don't know how to compute or demonstrate this. Does it make a difference if the room is considered big but closed or the room is open to atmosphere? If it makes difference for this discussion let's say that humidity of air in room is 25% RH and the room temperature is 25°C.