Short answer
Not safely for long: photos want 70°F or below and 30% to 50% humidity, held steady, which a regular unit can't promise. Heat fades color prints and damp air makes photos stick together and grow mold. For albums, negatives and slides, use climate control or keep them at home.
Photos are among the most fragile things people put in storage, and among the hardest to replace. A regular unit exposes them to the two things that ruin them fastest: heat and humidity.
What photos need
The Library of Congress recommends storing photographs at 70°F or below, at 30% to 50% relative humidity, in a stable environment with humidity changing by less than 5% in 24 hours. It also says to avoid attics and basements, which a non-climate unit closely resembles.
The National Archives gives similar numbers for institutions, about 65°F to 70°F and 35% to 50% RH, and warns that dampness “causes photos to stick together, and promotes mold growth.”
- 70°FUpper temperature for photos
- 30% to 50%Safe humidity range
- Under 5%Humidity change allowed in 24 hours
Color, negatives and slides are the most at risk
Not all photos age the same way. The National Archives says acetate negatives and color negatives, slides and prints are vulnerable to fading and deterioration within decades, even at room temperature.
Heat speeds that up. For acetate film, the Archives says cold temperatures slow but do not stop deterioration, and it recommends keeping humidity below 50%. A vinegar smell from old negatives is a sign they are already breaking down.
Home freezing isn’t the answer for most people. The Archives cautions that cold storage “can even cause more immediate damage if used improperly.”
Packing photos for storage
- Use safe enclosures. The National Archives says not to use office paper, kraft paper, PVC plastics or glassine. Look for enclosures that have passed the Photographic Activity Test (PAT).
- Replace old lab sleeves. The Archives notes that older enclosures from the photo lab may not be safe long term, though plastic slide boxes usually are.
- Store flat or upright, in archival boxes, not loose in a moving carton.
- Keep boxes off the floor and away from the unit door and outside walls.
- Label the outside so you don’t have to dig through prints to find what you need.
Make a copy first
Scanning your most important photos before storage costs little compared with losing them. Keep the digital copies somewhere other than the unit.
Regular unit or climate-controlled?
A regular unit is a poor choice for photos in almost any climate beyond a short spring or fall stay. In humid regions it’s a near-certain risk. A climate-controlled unit with humidity control, or a closet inside your home, is much safer.
Humidity is the main enemy in the Southeast. If you’re storing there, see climate-controlled storage in Atlanta, and ask each facility what humidity it holds.