This.
Keep storing the bottles in a cool spot in your home, then, when your friends start calling you a hoarder, consider offsite storage. I have a couple of “wine coolers” that are always packed full of wines I can drink now and my offsite is for my sleepers that I won’t touch for many years. Good luck and let us know what you decide.
Alicia - I don’t know what your home situation is like, but I have to agree that an 18 bottle unit is a waste of money. Put the wines in your fridge. Don’t worry about the humidity for God’s sake. If you worry, then wrap the bottles in Saran Wrap. You won’t have any issues then. The colder you keep your wine, the longer it takes to age.
“Aging” wine doesn’t mean keeping it for five, ten or fifteen years. As posted above, you don’t really start seeing what happens until 25 years or so. That’s not actually true - some wines have a faster aging curve than others, so if you want to age Beaujolais for example, and I certainly would, your ten year mark is the equivalent of a 20 year mark with some other wine. But if you’re trying to keep wines from Barolo, Bordeaux, Rioja, or even Washington, 10 years is meaningless.
Storing at 70 degrees for a few months is OK. For a year or two is OK. For 25 years I don’t know - I’ve never done it.
So again, decide what your purpose is. If it’s just to keep some wines till you get around to drinking them and you want to take advantage of sales, either keep the wines in the fridge or in the coolest spot of your house. And if you have to leave the AC on, even in a single room, the cost of the electricity is not nearly the cost of a fridge.
If the purpose is to store the wines for long aging, then buy big or do it offsite.
Storing 18 wines for 25 years will be a frustrating experience. What do you do then? Buy another 18?
Chris and the others raised good points. You need to see what your own plans are. It may be more expeditious for you to simply buy aged wines when you want them. I’ve been collecting wine for a long time and ended up with a few thousand bottles. Some people have more, some less. But now I’m able to drink some of those that I bought years ago, which was the whole point. OTOH, if you don’t care for mature wine, then just buy the most recent vintages and forego the cellaring and just keep a few bottles in the fridge.
Best of luck!
Thanks for all the additional insight! I’m not looking to “age” wines for long periods of time (at least not quiet yet)… so my apologies if I’m using that terminology incorrectly. But I do have a some wines (mostly California Pinots and Syrahs) I’ve bought this year that I’d like to hold on to for a few years or so and see how they develop over time. Basically my main concern is not ruining those wines.
You won’t ruin the wines if they’re just sitting in your apartment, so I wouldn’t worry about that. Unless they were sitting in direct sunlight baking daily. Other than that, they should be fine. I have offsite and then just a wood rack at home at holds 90 bottles. I haven’t had a bad bottle come from the rack.
Thanks for this. Fortunately, they are away from sunlight. This gives me a bit of relief, that at least so far… I probably haven’t killed them. 
Agree. I think there is a big misconception that one needs to store young wines in a cooler if your intention is to drink over the next few years. I keep my '05 & '10 Burgundies in off-site temperature controlled storage to drink 15+ years after the vintage. But for premium CDPs, for example, that I will drink youngish room temperature or cooler (basement) is fine.
Alicia, I recently went through a similar thought process. I wanted to keep a couple dozen or so bottles at home for near term drinking. I actually DO have a bunch of Bordeaux, Burgundy, Barolo (whee! the three B’s of bank account destruction!) that I’m aging long term, and I keep them in an off-site storage facility.
I have a perfect place to keep the bottles in a cool, dark corner of my garage, but I got all worried about the heating and cooling from my car engine, which I drive in and out every day.
I have a perfect place to keep the bottles in a cool, dark corner of the downstairs floor of my house which is delightfully cool year-round, but I got worried that my kids, dog, evil ghosts would get into the wine somehow. Or that we’d run the heat too high and the room would heat and cool. Or that the blinds would be left open and sunlight would hit the bottles. Or a thousand other dark fantasies.
Fundamentally I believe that you can keep wines at room temperature for months, even a few years, and it’s just not that big a deal, as long as they’re not getting cooked/hit by direct sun. At least the rational part of my mind believes it.
I just don’t really need a wine cooler at home, but I decided that for my peace of mind I would get one. It’s not for long-term storage, it’s just to keep the crazybrain calm and those delicious old bottles that I forked over good money for in worry free happiness until I pop them. Solution? An inexpensive wine cooler. It doesn’t have to be perfect. It’s not about long term storage. It’s not about the perfect conditions. It’s not about pristine labels. It’s about happiness and stress reduction.
So I guess I’m offering a different solution than everyone here. Though, if your rational brain is stronger than mine, then a box in the closet is your ideal answer.