I am writing from Israel and cross posting from the Israeli Wine forum in hopes of replies from people with experience doing this. By way of explanation, all dwellings in Israel are required to have a reinforced room to be used as a shelter in time of hostilities. It's called a Mamad, and that's the room I'm considering air-conditioning for wine storage. Hey, if I'm going to be stuck in the shelter I may as well have something good to drink (must make sure to keep some glasses in there). The room is about 7 x 9 ft. Unfortunately my house doesn't have a basement and adding one is not an option. Here's my posting from the other forum.
I'm considering air conditioning the Mamad (shelter) in my house to make it appropriate for wine storage. Up front cost is way lower than a wine fridge (100 - 150 bottles) and use of space is much more flexible. The A/C would also make the Mamad more useful as a pantry.
Another advantage is that the A/C moves the heat outside while a wine fridge essentially adds heat to the room.
For humidity I can either bleed some of the condensate from the A/C back into the room or just have a small bowl of water.
I haven't compared numbers yet, but I know that today's air conditioners are much more efficient than those of yesteryear, so I'm not sure how much more electricity the A/C would use vs. a wine fridge, especially since the Mamad will be closed most of the time.
The A/C guy tells me that most units will operate fine down to 20 deg C in the hot weather, with inverter units possibly going a bit lower (and possibly saving power too).
I don't intend to have very long term storage; with a very few exceptions, five or six years is probably the longest.
Has anyone done something like this? All thoughts and comments more than welcome.