Ancient Manuscript Silica Gel Humidity Buffer Calculator

Mass balance for silica gel buffers

Archival microclimates hinge on balancing the water vapor entering a storage enclosure with the capacity of buffering materials. Silica gel adsorbs moisture within its porous network, behaving as a reservoir that keeps relative humidity within an acceptable band. The total moisture load is the product of ingress rate and duration, while the gel mass required scales inversely with moisture capacity. The core relationships implemented here are:

where $W$ is water mass in grams, $w$ is ingress per day, $t$ is the number of days, and $c$ is the capacity percentage of the gel at the target relative humidity. Pack counts and costs follow directly from dividing by the chosen packet size and multiplying by the price per kilogram.

Sample buffering scenarios

Conservators often evaluate multiple risk levels such as normal operations, a leaky door seal, or a prolonged outage. The table below compares silica gel requirements for a 14-day buffer at different ingress rates using 10 % capacity packets.

Adjusting capacity accounts for different target relative humidities. At 40 % RH, the same silica gel might hold closer to 7 % water by mass, increasing the required packets and cost. Use the calculator to experiment with these sensitivities before committing to a purchase.