Good looking and with a simple layout, the big Argos 415/8484 unit scored well on usability, with an easy-to-check 3.6-litre tank and a viewing window. A main dial controls humidity, while a second switch regulates fan speed. Unfortunately, though, we noticed that the fan had a noticeable hum all the time the 415/8484 was running - even when it was on the lowest setting. Moisture extraction proved better than with most of the sub-΂£100 models here, but on the minus side the unit works effectively only down to 5oC.