I agree. If you are distilling water for analytical use you would start with deionised water as anything volatile in the source water could be carried over in the vapour and end up in condensate. But for use in a washer bottle, I’d have thought tumble drier condensate would be good enough. Probably better than the water from an air conditioner as there is a fluff filter in a tumble drier.

Timely - Its now the time of year when we start to use our tumble dryer so I'll be able to collect the condesate. Jules