[ajuc]

The water that was in your clothes and evaporated over 12 hours at night naturally is the same water that evaporates in 1 hour in the powered dryer.

If you have working ventillation you're fine either way. If not - you're not. In fact I'd expect worse problems if you evaporate that same water quicker, because there's less time for it to escape outside.

[powersnail]

Usually dryers are connected to dedicated ventilation out of the house, so the humidity doesn't transfer into your room directly. Otherwise, the laundry room would be a sauna.

[lolinder]

Dryers typically are vented immediately outside via a dedicated tube and vent. That means that the air in the rest of the house never sees the moisture at all, so your whole-house ventilation system or dehumidifier doesn't need to work as hard.

[ajuc]

Thanks, now that I think about it that makes sense :)

[CalRobert]

Some driers, especially in Europe, condense the water in to a tank that you empty manually in to a sink. This is useful if you don't have an easy way to vent it and also shows just how much water is coming out of your clothes (multiple liters per load, sometimes!)

[ponector]

If your room has already high humidity level water does evaporate really slow and the next day you get smelly clothes.