Bought a Toshiba Aircon unit from a classified ad and it works in a
slightly different way to my other aircon unit (B&Q) and I wondered
why.

Its a floor standing unit on wheels with an exhaust hose which goes
through a hole in the wall, same as the B&Q unit.

However, it has a large water tank which needs refilling, whereas the
B&Q one doesn't. It's NOT an evaporative cooler, so what is the water
needed for?

It works *really* well, far better than the B&Q model so the water is
obviously doing something..but what?

shokka