The problem with wood in this situation, all situations really, is called wood movement. Wood slowly absorbs moisture over time and as it does so it expands. One problem is it doesn’t expand equally or uniformly. Woodworkers know all this and here you can actually calculate how much your rack will move (expand) in your basement https://www.woodworkerssource.com/estimate-wood-movement.html
MDF is wood and so no different, except that with MDF it distorts all ugly and loses all strength and never goes back like wood does when moved to low humidity. I would avoid MDF unless dirt cheap and used with the knowledge it may well be a total loss if used there long enough.
If you still want wood I would look for a rack that uses wood legs with steel or other hardware attached, as opposed to a solid wood rack where everything is wood connected to wood. That type of construction the movement can physically tear the joints apart unless they were properly designed for this. Since you already know the manufacturer specifies a lower humidity then guess what, it was not designed for this!
You can still use wood, you just need to be aware and think very carefully. Otherwise you wind up like a friend of mine, spent months building this beautiful cabinet and when he showed me I said why’s this piece sticking out half an inch? "Wasn’t like that when I put it together!!!" He didn’t know about wood movement. Once you do, look around, people that build stuff like cabinets, raised panel doors, there is a lot more skill and knowledge involved than appears at first glance.
MDF is wood and so no different, except that with MDF it distorts all ugly and loses all strength and never goes back like wood does when moved to low humidity. I would avoid MDF unless dirt cheap and used with the knowledge it may well be a total loss if used there long enough.
If you still want wood I would look for a rack that uses wood legs with steel or other hardware attached, as opposed to a solid wood rack where everything is wood connected to wood. That type of construction the movement can physically tear the joints apart unless they were properly designed for this. Since you already know the manufacturer specifies a lower humidity then guess what, it was not designed for this!
You can still use wood, you just need to be aware and think very carefully. Otherwise you wind up like a friend of mine, spent months building this beautiful cabinet and when he showed me I said why’s this piece sticking out half an inch? "Wasn’t like that when I put it together!!!" He didn’t know about wood movement. Once you do, look around, people that build stuff like cabinets, raised panel doors, there is a lot more skill and knowledge involved than appears at first glance.