Guideline 10.2: Enclosures are carefully designed and fabricated to promote object safety and ensure they meet the Conservation Requirements
Why is appropriate design and fabrication of cases essential?
Conservation scientists have established that the protection provided by an exhibit case depends upon correct case design and careful fabrication. A poorly designed case not only fails to protect objects, it can actually accelerate their deterioration by entombing them in a hazardous environment. And a well-designed case that is poorly constructed will be equally damaging. In case design, the following sources of damage must be avoided:
Unsafe construction materials: It is critically important that chemically unstable construction materials are not used in case construction. Only non-hazardous, non-emitting materials should be used in the display and maintenance chambers. Even a small amount of continuous out-gassing from a small quantity of construction materials can raise chemical concentrations to hazardous levels in confined spaces. A physical barrier can be used to isolate potentially out-gassing materials from the display chamber. (For more information on non-hazardous materials see Standard *.)
- Overheating: Heat from lights, fixtures, transformers and fan motors can build up inside a sealed case. The lighting plan and ventilation design must prevent overheating.
- Faulty placement of the case: Placing a sealed case near heating or air-conditioning ducts or return vents or near a door or window can interfere with the climate inside the case. And placement against a building’s external wall could affect the internal temperature and humidity of the case.
- Access for pests: Poorly sealed cases can provide insects and rodents with a place to find harborage and an easy path to food.
- Inadequate locks: A poorly-designed locking system can prevent rapid access by a curator in an emergency. Conversely, easily accessible, removable panels can allow unauthorized access.
- Microorganisms in hot and humid climates: A well-sealed case in hot and humid climates can have problems with microorganisms. Because ventilation is reduced within the enclosure, high-levels of humidity can continue long enough for germination to occur (prolonged periods in excess of 70% RH.). Ventilation can be designed in and desiccants can be included to lower RH.
The following Subject Headings are placeholders for the huge amount of information necessary to create an adequate Standard and Guidelines for case design.
- What security options are available in exhibit case design?
- What exhibit case features protect exhibit objects from physical damage?
- What options are available to protect objects from water damage and fire?
- What lighting options are available to protect objects from inappropriate light exposure in cases?
- What options are available to protect objects from inappropriate humidity fluctuations in cases?
- What options are available to protect objects from inappropriate temperature in cases?
- What options are available to protect objects from pollutants and contaminants in cases?
- What design features in cases protect objects from pests?