My mother was a librarian, and I got my enjoy of books from her. When I was a child I started to collect books, which is a activity I still have to this very day; Most books are somewhat disposable, especially the paperback books. These volumes were not designed to stand the test of time, they were meant to be study and given away. I do have a very sizable collection of precious and antique books, some of which are over 200 years old; For these precious volumes I have a separate learning room with its own custom temperature control system to ensure the books stay in the best possible condition. The older books are the most delicate, so my Heating and A/C system has a rigidly enforced set of parameters to maintain the room at precise air quality levels; Some of these books are so seasoned I can’t handle them without wearing latex gloves! The learning room remains sealed at all times, so that the air quality isn’t contaminated by the rest of the house. In the event of a power outage, I have a small generator under the apartment connected solely to the Heating and A/C system of the learning room, even if the rest of the apartment loses power and A/C I know that my books will remain safe. These books are worth a lot of cash, but have even good sentimental value to me, so the custom Heating and A/C system was a very wise investment. If you can’t afford something so lavish for your book collection, I recommend at least getting a dehumidifier.