This is very weird, I've opened that thing this year and nothing came out, do the water then evaporated the from last year and the current year? o.O

I have this too and yes, there is a tank. We call this "condensation water". The tank is on the bottom and there is a "opening Part" like on Pic Number 3 of the product, where you can empty the tank. Just but a box or something else under it and let the water out.