Window Vacs for condensation

[R2x1]

It's not terribly useful for a flatting situation but as a homeowner I put some effort into venting the moisture out of my house by adding an extractor fan to the bathroom, a rangehood to the kitchen, venting the dryer outside, and I also have double glazing. The net effect is I don't get much moisture on my windows at all and don't bother wiping it when I do get some. Windows have their own drain system anyway, just make sure the drain holes aren't clogged up.

You may not want to do this in winter but you can get a lot of the benefit by opening a window at opposite sides of the building for 10-15 min a day and letting the air circulate. Or running a dehumidifier but I never liked them all that much.

Sorry if it's not a helpful comment, it just seems like wiping up the water is treating a symptom and not addressing the cause to me.

It's a very popular modus operandi (usually for a lot more than 15 minutes a day). Although New Zealand is a small country, leaving doors and/or windows open means you're not only trying to heat NZ, but, due to our leaky coastline, you are also going to be tackling either the Tasman Sea or the Pacific Ocean. Either is a pretty big task unless your heating/cooling  unit is a bit bigger than most domestic units.
Out of curiosity, is it recommended to have the windows you plan to leave open double glazed, or are they better off single glazed? I suppose it could be best to simply take those two windows out completely?
I don't greatly like the noise or the running cost of our dehumidifier, but I don't like the water it collects either - up to 7-1/2 litres a day if the wind is from the North East.     I shudder to think how much water I'd be dumping if a couple of windows were open. It might help with sea level rises I guess if I try to dehumidify the air over the Pacific, but alas the condensate is going back to the ocean pretty soon.