Donna Pacheco of Achadinha Cheese Company
told me that she ages her cheese at 55°F and 80% relative humidity. That's about the same conditions you would find in a natural cave, perfect for aging cheese. (See the last step for details on the cheese I'm aging.)
The crawl space under my house is pretty cool most of the year, and I even measured the temperature of the ground a few inches below the surface at 59°F. However, there are vents to the outside, so the humidity is the same as ambient, and it rarely gets as high as 80%. I briefly considered converting a pantry with an exterior wall into a temperature-controlled cave using a window air conditioner and CoolBot controller
-- but you know things are getting out of hand when you consider cutting holes in the wall for cheese you haven't yet tasted. In the end, I decided to follow the rough outline of the Converting a fridge for fermenting beer Instructable
, and use a small fridge with a temperature controller placed in the crawlspace.