Laundy room redo which kind of drywall
I agree with the poster that said to install a vent, like in a bathroom. If you do have a humidity problem, it would be better to fix the problem, instead of trying to minimize the symptoms (ie mold and wall damage). I don't know definitively, but I've heard many people say the greenboard doesn't really help much compared to normal drywall as long as you prime and paint well. And concrete backer board wouldn't do much to help. The difference between concrete board and gypsum products is that water can penetrate concrete without hurting it, whereas gypsum turns to mush. But concrete can still get moldy.