Just check the operating temperatures - the cheap ones that Aldi sell will not work below 10C. They rely on ambient temperature to thaw the captured moisture, which turn to ice. Anything below 10c and the ice does not melt before the cooling unit kicks back in (not adjustable time period), resulting in more cooling which equals one big block of ice at the rear, which funnily cools the motorhome down even more.
My experience too .
The type of humidifier supplied by Ebac etc, which costs a lot more has a forced thawing system, which will operate to lower temperatures, but again struggles when in a cold place.
If you have bought it to keep unheated motor home damp free in winter - then it is unlikely to work. Better return it and get money back when you can.
Only my thoughts having bought 3 cheap ones before giving up. The home one (ebac) works better, but again won’t work when it gets really cold.
It will be: as its trying to dehumidify Nottinghamshire,that is unless you have it sitting in a 100% air tight space, then it will reduce the water vapour content of the air, that is until you open the door when the water vapour pressure will immediately balance with the ambient.This one is half full after about a week working really well