Passive Climate Control
Source: Cornell University Library,Library Preservation and Conservation Tutorial
Because of high energy costs and the impracticality of HVAC for many libraries and archives, there is now a great deal of interest in passive climate control systems. In tropical climates, HVAC can have serious detrimental effects, especially if it cannot be operated on a continuous basis. Generally, HVAC is used to cool spaces, but in climates with very high humidity it does not function well enough as a dehumidifier to ensure effective climate control, and must often be used in combination with dehumidifiers. When HVAC cannot be used continuously—for example, when it is shut down at night or on weekends—the air heats up and condensation forms on the colder surfaces of books, shelves, and walls, resulting in mold growth.