| Prevention and treatment of mold in library collections with an emphasis on tropical climates: A RAMP study |
|4.2 Interior modifications in existing facilities|
Stacks should not be placed directly against exterior walls as heat and moisture transfer is greatest there, and circulation will be severely limited. Even a foot of air space between the wall and the stack will improve circulation and prevent condensation of moisture on the wall from creating a micro-climate.
Stacks should be arranged parallel to the air flow, so that the prevailing air movement is across the spines of the books as they stand on the shelves. Stacks should never block air flow from existing windows or ventilation created by fans.
Stacks should be open backed, particularly free standing stacks which are joined at the back. This will improve the ventilation on all sides of the volumes. If strength or stability of the stacks is a concern, cross braces should be used rather than the solid panel supports provided in many commercially available stacks. Compact shelving, however desirable from the stand point of space saving, should be avoided in the tropics, primarily because a micro-environment may be created when the stacks are closed. In addition, the mechanisms for moving the stacks tend to become inoperable in high humidities.
Closed cabinets should be avoided whenever possible. If they are necessary for the storage of microfilm or locked case books both the back and front of the cabinet should be ventilated, or a favorable microclimate should be created in the closed cabinet to counteract the high relative humidity.