Tumble drying versus airing

Over the summer our electricity bill almost vanishes as we put stuff out on the line from the crack of dawn and don’t use the lights much either. Winter however is another matter entirely. Our washing machine (a Bosch, since you asked), has a 1,400 RPM spin cycle which you would think is enough to get most of the moisture out of whatever it washes. It turns out this isn’t the case though…

Since we had our garage converted and I accidentally burnt the motor out on our old tumble dryer (the washing machine had packed up and I put a ton of sodden clothing straight into the dryer, which immediately couldn’t cope with the weight), we’ve had a condensing tumble dryer rather than an externally venting one. This means I can keep a fairly close eye on the amount of moisture that the tumble dryer extracts from our clothing.

This is the result of a mornings worth of tumble drying:

Now imagine sticking those three loads of washing on an airer. That moisture has to go somewhere, and the chances are if you’ve not got the windows open (for example it’s pissing it down, which is the reason your clothes aren’t up on the line in the first place), it’s going to get absorbed by your wallpaper and soft furnishings. 
I suppose you could spend some money on a dehumidifier to capture the excess moisture but that sort of seems to defeat the purpose really. That’s why we tumble dry stuff in preference to using an airer. It might be massively more expensive but at least I know where the water is going…