Temperature/Humidity Levels for UCSD Libraries

UCSD environmental levels are based on the Solinet Environmental Specifications for the Storage of Library & Archival Materials. Rapid fluctuations do the most damage to collections. The goal is to maintain constancy within the specified ranges for temperature, and for humidity, accommodate seasonal fluctuations, but minimize daily and weekly variations. Maintaining good air circulation is important, and staff should report any problems with decreased air flow.

In the UCSD Libraries, the HVAC systems are not able to humidify or dehumidify collections areas (except for dehumidification in the Mandeville closed stacks and the SIO Rare Book Room.) We can only affect the humidity by manipulating the fresh air mix and the temperature.

Following are the recommended environmental ranges for books, paper, and people.

General Stacks (Annex, Geisel, and Branch Libraries):

Temp	68-72° F	±5° F
Relative humidity	40-55%	±3%

Report temperature in excess of 77° F and/or RH over 58% that continues for more than 24 hours. If you anticipate conditions may persist over a weekend or holiday, report it immediately.

Branch staff should be alert to any changes in environmental conditions, and view and/or download data at least monthly and more often if hot and/or humid conditions are present.

Following are the recommended environmental ranges for UCSD closed stacks.

Mandeville and SIO Rare Book Room:

Temp	60° F	±5° F
Relative humidity	45%	±5%

Music/Film Closed Stacks:

Temp	60° F	±5° F
Relative humidity	50%	±5%

Return to: Responsibilities for Environmental Monitoring for Collection Preservation