Library Questions: Why is it freezing in here?!
It's a question we get quite often: Can't you turn the temperature up? And we understand why you're asking! Sometimes it can feel a little chilly in the library. But we promise there's a good reason for the temperature!
The books! The temperature we set the library to has less to do with the outside temperature (though in Oklahoma, that is always a consideration), and more to do with humidity. You don't want the relative humidity to be too high or too low. Both extremes can damage books. Instead, we try to keep it in a sweet spot.
Natalie Granados wrote a great article on the topic for the University of Connecticut for Preservation Week, so I'll be quoting from her article since she's an expert!
“How is humidity measured?” you may wonder. This is where the term Relative Humidity (RH) comes into play. RH refers to the amount of water vapor in the air, expressed as a percentage of the maximum amount the air could hold at the same temperature. . . Cellulose, as the raw material of paper, is hygroscopic. This means it responds to changes in relative humidity by expanding when humidity levels are high and contracting when they are low. . . low RH results in shrinkage, cracking and desiccation of paper and adhesives and flaking of photographic emulsions. Desiccated paper is more easily torn when handled. It must be noted, that structural water, unlike the surface kind, cannot be regained. Other damages caused by low RH include stiffening and flaking of adhesives and emulsions on photographs. High humidity on the other hand, can lead to insect activity, delamination, bleeding of watercolors,distortions, adhesions of coated paper, ink transfer and mold growth. Mold stains and weakens paper and leather."
(This is just a snippet of the article. To read the whole thing: visit this link.)
What we are most concerned with at the Duncan Public Library is high humidity; our building's HVAC and the constant in-and-out of people can't keep our relative humidity low enough to damage books in that way. But our humidity can get too high, which is where the A/C comes in! Air conditioners don't just cool, they dehumidify too! That being said, sometimes you'll also see us run dehumidifiers too, just to be extra safe when it's very humid outside.
And admittedly, part of the consideration is the size of our building. We are lucky to have such a large and open building, but that does come with challenges for heating and cooling. We have to battle temperature fluctuations in large open spaces and our beautiful floor to ceiling windows/skylight. It's easier to keep the building one stable temperature inside, regardless of what temperature it is outside.
So, what can you do? The easiest thing to do would be to make like a Librarian and bring a cardigan with you to the library just in case.
Do you have any other library questions you'd like answered? Let us know!
