Dear Georgios, Lighting with 100% luminous efficacy does not exist. All types of (LED) lighting produce some heat. However, I can give you some general advice: 1. If you can, place the driver electronics outside of the case, so that their heat will not be produced inside the case. If you put LED tubes in ordinary fluorescent tube fixtures inside the case, you will have the power conversion losses happening inside the case. 2. LED strips, which usually have an adhesive backing, are very easy to install in custom lengths, and make it easy for you to put the driver electronics a bit farther away, outside the case. This is probably the easiest option if you make larger display cases. 3. Should this still generate too much heat, you can use fiber optics to transport the light inside the case, but have the actual light source outside the case. This type of lighting is often used in small display cases, where the heat builts up quicker than in very large display cases. See for example the products of Luxam. I am sure there are other or locally available brands too. 4. In general, pay close attention to the color rendering specifications of the LED lights, often expressed as Color Rendering Index (CRI). This needs to be as close to 100 as possible. Unfortunately, the higher the CRI, the lower the luminous efficacy usually is, and the more heat you get. This also works the other way around: the most efficient LEDs often have very poor color rendering properties, and these should never be used for displaying works of art. Yuji International make and sell very high CRI LED strips on a reel, and the corresponding driver electronics, if you like to DIY.
Best of luck, and kind regards, Thomas Michgelsen ****** Unsubscribe by sending a message to [email protected] Searchable archives: http://cool.conservation-us.org/byform/mailing-lists/cdl/
