Guideline 15.4: The lighting plan controls Infrared Radiation
Why should infrared radiation be controlled?
Infrared radiation (IR) should be controlled because it does not contribute to visibility and yet can seriously interfere with efforts to regulate the museum environment.
IR has a wavelength just greater than the light at the red end of the visible light spectrum. Although human beings cannot see IR, we experience it as the main source of heat in sunlight and incandescent lights. Heat can be very damaging to objects. It can cause an exponential rise in the rate of object deterioration by speeding chemical reactions and drying out organic materials. It can also influence relative humidity and the moisture content of objects on display. Research also attributes up to 40% of color loss in dyes to IR radiation.
In fact, more than 90% of the energy from an incandescent lamp is heat, and every watt of light adds 4.15 BTUs (British Thermal Units) to the heat load of the building. The IR produced by lighting is therefore an important consideration in efforts to control temperature and relative humidity in an exhibit. It is also a budgeting consideration: some exhibitions incur air-conditioning expenses year-round as a result of the heat produced by poorly designed lighting systems.
What methods can be used to control Infrared Radiation?
- Utilize lighting systems that do not generate heat: LED lighting, compact fluorescents. [More information required]
- Dissipate heat generated from exhibit lights to prevent buildup in confined spaces within, above, or next to exhibit cases or objects. [How exactly?]
- Locate objects at distance from lights: position objects at least 24 inches from fluorescent lights and at least 36 inches from incandescent or tungsten halogen lights.
- Insulate light box in cases to prevent heat building up inside the case where objects are housed.
[For more information on cases see Standard *]