Welcome to Day 2 of Preservation Week 2025! To see other posts in this series, follow these links:

Day 1: Curatorial meetings
Day 2: Presenting our HVAC pilot project
Day 3: Using UV light to analyze materials
Day 4: Discovering details in book bindings
Day 5: Field trip! Gathering damaged books from Circulation points

Last year, in response to the Duke Climate Commitment, we tested an overnight HVAC shutdown pilot project during the winter months in the circulating collections. We wanted to see if the University could reduce its carbon footprint while maintaining adequate environmental conditions our collections. We worked closely with Duke Facilities to determine how to implement this program. You might recall at the beginning of the project we placed an Onset HOBO MX1101 datalogger inside a discarded book to see how it responded to changes in temperature and humidity in the stacks during the HVAC shutdown project.

We noticed some curious readings and decided that the amount of hollowed-out material likely affected the way the text block reacted to changes in humidity and temperature. This winter we created a second test book but this time we used a probe-style Onset HOBO 2302 datalogger. Our working theory was that a smaller hole in the middle of the book would give us better data.

I grabbed a book from the discard pile and started cutting. Once I hollowed out a space for the probe, I created an Ethafoam plug to minimize air filtration at the fore edge.

The books were placed side by side on the shelf with books on either side to ensure they stayed closed. This area of the stacks contain mobile shelving, which are opened and closed regularly as patrons use the aisle.

I looked at the last 30 days of data from this datalogger in preparation for a talk about this project at the State Energy Conference today. You can see the old book (blue line) vs. the new book (green line) both react slowly to changing conditions. However, you can also clearly see the book with the smaller hole is reacting more slowly to changes in humidity (temperatures remain very stable).  Both books are slower to react to ambient rH conditions. But you can definitely see a difference between the two books, which I think is at least partially due to the amount of material excavated from the center of the book.

Tom Young, Critical Systems Controls Engineer in Duke Facilities Management, and I are excited to share our findings with the conference attendees today. Spoiler alert: the energy savings were substantial and the books are fine.