Dehumidification is an important recovery method used in the preservation and conservation of library materials, particularly when books, manuscripts, documents, photographs, maps, and other paper-based materials are exposed to excessive moisture or water. High humidity can cause serious damage to library collections by producing swelling, distortion, staining, ink bleeding, mould growth, unpleasant odours, and weakening of paper and bindings. Dehumidification helps to reduce the moisture content of the environment and materials in a controlled manner, thereby preventing further deterioration and making damaged materials suitable for subsequent conservation treatment. The method is especially useful after disasters such as floods, leaking roofs, burst water pipes, heavy rainfall, or accidental water discharge in library buildings. When books become wet, immediate drying is essential because mould can begin developing rapidly under warm and humid conditions. Dehumidification removes moisture from the air and lowers the relative humidity of the affected area. This creates an environment in which evaporation from wet library materials can occur more effectively while reducing the conditions favourable for fungal growth. In disaster recovery, industrial or portable dehumidifiers may be installed in the