Cold Storage Vaults
When film-based collections are large and require more than 150 cubic feet of space, the equivalent of about ten household freezers, consider the installation of a cold storage vault. The cost, energy consumption and space needed for so many freezers may make the vault a more efficient option. It may also be more cost-effective to purchase a vault if the collection is predicted to grow beyond a size that may require many freezers.
Cold storage vaults are self-contained, refrigerated, pre-fabricated modular structures made from insulated metal panels . They can be purchased in standard sizes or they can be customized to fit your collection needs. Vaults can be maintained at temperatures slightly above freezing (35◦F) to accommodate access and reduce energy costs. Although vaults can be humidity-controlled, such a feature will significantly add to energy consumption. Opting for only passive humidity control is a good option; however, this will require the addition of cold storage packaging, as described in this program. A wide variety of storage furniture options, including simple wire racks, shelving on casters and compact shelving units, are available depending on your budget and the size of your collection.
When are vaults an option for your collection?
- collection takes up more than 150 cubic feet (10 household freezers)
- collection is expected to grow beyond a size that can be stored in 10 household freezers
Smithsonian Vaults
Now we're going to look at a few different options for cool and cold storage areas other than the upright household freezer we already explored. Today we're with Sarah Stauderman, and we're at the smithsonian archives in Washington, D.C. now, the smithsonian archives has a large collection, so they decided to build a cold storage vault to house their materials.
What type of vault is this?
Well, this is a walk-in freezer without humidity control. We have it set at 4 degrees fahrenheit, and that's for the long-term preservation of our acetate negatives, but it's also for pest control for collections that might have had an insect infestation, and the nice thing about this vault is that because it does not have humidity control, it's less expensive to build.
How do you prepare your materials to go into the freezer?
Well, we use a model that was demonstrated by the city of vancouver archives. That uses gasketed cabinets to passively control the humidity of the cabinets using silica gel. And so we don't have to do any kind of vapor barrier packaging with our collections. We can directly place the collections on the shelves in the cabinets in the vault.
And if you need to retrieve something from the vault, how do you do that?
We use a cooler. I find out what collections need to be retrieved, I go into the vault, move the collection into the cooler, and then I come out of the vault. Then I wait for 24 hours, and at that point the item should have warmed up to room temperature, and you can use that system, or you could use a plastic bag, anything that would help protect the collection as it's going from a very cold environment to a warm environment, so that you're reducing the risk of condensation as you're crossing dew point.
This is our cool room environment. We keep our temperature at 60 degrees fahrenheit, 50% relative humidity year round. That means that our collections are benefiting from a lower temperature and relative humidity. It also means that we can easily access collections and bring them into our reference room without concerns for any type of condensation or crossing dew point.
Last updated: December 18, 2019