Posted by peak4 on 12/01/2016 12:57:34:
I'm not sure I'd want to leave it running full bore all the time though for cost reasons – it seems to be rated @ 250W
Not arguing with you but just to calibrate the discussion (for my own understanding), 1kWh seems to cost about 12p, so if this device ran flat out it would cost about 3p/hour or 75p/day or £22/month. They probably have humidistats and the humidity probably varies during the day anyway so that's a worst case figure.
Incidentally, if you look at the cost of running a conventional clothes drier, the heat of evaporation results in a cost of about 10p / litre of water. These humidifiers are heat-pump based, so the cost of recovering a kg of water with a dehumidifier is a fair bit less, like about 1/3 the cost of boiling it off the other way.
I have one of those new-fangled "A***" heat pump clothes driers and plan to measure it using a plug-in energy meter. Should be similarly frugal. There is no external vent pipe, only a condensate drain pipe and the amount of heat given off is very small. Makes some funny noises, mind!