Updating this slightly old thread as we're still very much in winter but I now have several weeks use on the Ecoair dessicant that I bought in the autumn.
What I find myself doing is just running the machine on high for it's minimum 2hr timer setting if I'm in the garage and it's feeling damp. I'm happy to leave it on the timer after I leave so that the damp air that comes in through the door as I leave is reduced.
A few times a week at a cost of under 20p per 2hr session is not going to break the bank.
Earlier in winter, 2hrs would knock the humidity down from say 78% to 68%
In the last week, it is taking 90% down to 79% each time.
Because the DH puts out a little bit of heat and the drier air is less chilling, it makes the place a lot nicer to work in without putting on an electric fan heater.
I just decanted 2 litres of water from the tank today. It grabbed that in 2x 2hr sessions. 2 litres feels like a fair weight of water when you're trying not to spill it on the way to the sink.
The place feels a lot better because of the new drier. I'm glad I bought it.