Yes, also of course the main reason we tend to suffer in this country is the high humidity we get with the heat, hardly surprising as the UK is surrounded with water of course, but when you sweat you expect the evaporation of the moisture to cool you, but it won't because the air is almost saturated already. The only answer is to alter the pressure or move the air over you to use as much of the little bit left of room for moisture onto your skin. Likewise these devices try to so the same with a wet filter of some kind, As I have noted before, there are some larger units, often seen abroad that also seem to have a dehumidifier of some kind. I'm not saying they are better, but subjectively they are, but you end up with a tank of warm water at the bottom, and a bigger leccy bill. ahem. The most efficient way is the closed loop system with a material that can be evaporated at different temperature, ie an air conditioning unit, basically a large version of a fridge heat pump, where the excess heat is outside not in the room with you. Brian