this is the way.
re: lowering humidity, i have two computer fans running inside my wine fridge in the warmer months. you just snake a thin usb cord through the door and it works perfectly. has the added benefit of greatly increasing the efficiency of the unit itself as the air circulates better. just search for usb computer fans.
Keep in mind that even if the fridge air temps swing like this the temperature in the bottles is hardly moving, probably on the order of 1 degree. At least that’s how I reassure myself. Haven’t noticed any protruding or sunken corks either so that would be the other main concern.
I would worry about messing with the door seal doing this, I guess if you get a flat cord it would be ok?
flat is fine but you can run super thin single wires through. the seal isn’t affected.
Thanks! Curious also as to how you have the fan oriented to increase airflow. May try this, I mean why not at this point? 
i have one velrco’d to the top and one on the bottom. the fridge fans are in the middle (one of those two-zone bois) and i leave them on all the time.
i use these for drying ducks and chickens in the fridge too. proper fridge not wine fridge
How do the fans lower the humidity? If they are in an enclosed space, you’ll just be moving around the humid air.
enclosed, but not hermetically sealed so there’s air exchange with the outside world. the unit by default tries to maintain a temp and humidity within a range and its ability to do so is dependent on ambient conditions. if the ambient conditions are such that it’s struggling, then an internal fan moving the air makes it more efficient. think how a convection oven works.
I’m having the opposite problem to many of the people above, with an ~140 bottle wine cooler that is great at keeping temp at 54 but holds at 40% humidity. This has been a reliable cooler otherwise. Yes, I live in a humid climate and could just open the fridge door regularly but that’s not realistic for us.
First, should I care about the low humidity for long term storage? In the absence of reliable studies, anecdotal experiences/ more comparison tastings welcome. And second, anyone have a good hack for increasing humidity in a wine cooler, preferably one that takes up about the space of a single bottle?
I have a couple of ideas in the process of implementation but am curious about other ideas. FWIW, I’m not convinced humidor inserts are likely to be too helpful but wonder if anyone’s actually tried this. The challenge is weakening the meniscus and the standard solution would involve a fan (but could involve a wick).
IMO not at all. 40% isn’t that low and the bottles are on their sides with liquid up against the cork.
That’s my thinking but every once in a while I let the hype get to me. The bottles are on their side and 40% shouldn’t be an issue. That said, I’ve raised the temperature to 60F on the thought that there’s a positive relationship between heat and humidity extraction. There are no champagnes in that cooler.
I did buy a couple of cheap battery run humidifiers before seeing my overreaction that I’ll test out for fun and report back in case anyone here is looking to address a super dry wine cooler.