There is a small refrigerator without a freezer section in each concierge room. They are adequate for keeping maybe 18-24 cans cold--not ice cold (if it's summer), but cold enough to drink.
Water (and canned Coke product soda) is part of the concierge service and is available 24 hours a day in the lounge. You are free to stock your refrigerator or just take the drinks as you need from the lounge.