Lighting Question

Viewing 9 reply threads
  • Author
    Posts
    • #133262
      Jay
      Member

      Does anyone have any suggestions for lighting in a storage room that houses archives boxes and a few oversized artifacts? The room is not used on a daily basis. Thanks a lot for any help.

    • #133271
      Jay
      Member

      I’m not sure why my post is listed 3 different times. Sorry about that…

    • #133270

      No worries Jay, we went through and removed the extra posts.

    • #133269
      Richard Kerschner
      Participant

      We light our storage areas with low cost efficient commercial fluorescent light fixtures that mount tight against the ceiling and are covered with polycarbonate covers to effectively eliminate UV radiation. We light the spaces well so that we can easily find and safely handle stored artifacts. Since the lights are off for and average of probably 23 hours a day, exhibit light preservation standards of 15-20fc for painted artifacts and 5fc for textiles and works of art on paper really do not apply. Instead, we turn to total exposure per year guidelines and stay way under those limits.

      That being said, one must then ensure that they do not place a workspace in the storage areas and turn the lights on for several hours a day to light up a few tables for staff or volunteers to work at, or if they do to light those tables with task lights. In other words, use common sense and don’t work in storage areas for extended periods of time.

    • #133268

      Motion sensors are often good idea for reducing light exposure and saving energy. Without knowing the size and scale of your room, it’s difficult to provide specific lighting suggestions.

      Typically, linear florescents are great choice, but they need to be filtered for UV. Compact florescents (spiral lamps) are much more difficult to filter for UV. LED’s are not quite a mature technology, but I have a lot of confidence in the Philips AmbientLED LEDs that work like standard lightbulbs(they are yellow, until they are illuminated). LEDs typically do not produce UV. Regular incandescent light-bulbs are low enough in UV so also don’t typically need to be filtered. However, incandescents get warm, need to be changed often and are energy inefficient.

      Just like in museum exhibits the goal is to provide enough light to see well, while light in excess of what is required increases the rate of damage for no reason. If it’s truly just a storage room and no object conditioning or viewing of objects is necessary; then I guess the lighting only has to bright enough for safe passage and to inspect for insect or water damage

    • #133267

      There are a lot of new LED’s of various configurations that have high quality color rendering. Aside from the no-UV advantage, they emit very little heat and use much less energy even than fluorescents. If you are using motion detectors, there’s another advantage – unlike fluorescents they fire immediately. In ordinary use they last about 20 years, so in this case, they will last well past your retirement!

      Actually, I often recommend a relatively high light level in storerooms to make sure that dangerous conditions – drips or powdery objects or bugs – are visible without much effort.

    • #133266

      OK, if Rick, Scott and Barbara jumped in with the LED bandwagon, they probably knew I would eventually write! I’m somewhat known as an LED humbug, but without good cause, I’m afraid. I like LED’s in the right situation and as long as we all admit what we are getting into!

      * LED technology is extremely efficient and the spectral power distribution ( SPD or color distribution emitted by the lamp and therefore true color rendering of light reflecting off any surface)is getting better and better. So I see them as a good choice for storage where the heat-sink and dissipation fins of the lamps are not enclosed in a enclosure such as a track lighting can or unvented recessed lighting can.

      * We really have no idea how long LED’s will last. They CLAIM to last 20 years but NONE of the better phosphor blends and heat sink technologies have even existed for 3 years,at this point! So NOBODY has a twenty year old lamp that has actually stood the test of time.

      * Be aware that LED’s are at the “edge of thinking” in commercial lighting and that there are several things that DO go wrong in testing thus far that impact life:

      * As with all light sources, output decreases with time. With LED’s we just don’t don’t know how much and how fast. All the “lamp lifetime” data are interpolations of very short test periods.

      * Multi-Phosphor LED’s use phosphors – powders that absorb the UV light created by the LED diode and emit visible light (yes-LED’s do create UV; they actually create visible light using invisible UV light. It’s just captured within the collimation lens). Those powders are heat sensitive. That means that nice, balanced white light may quickly change color – become more green, blue or even magenta as the phosphors break down from heat. The light may still “work” for 20 years, but you might not want to use it.

      My point here is that if you sell your CFO on LED’s that will last 25 years and they loose their color after 5 years, you may find finance people knocking on your door with an axe. On the other hand, if everybody gets that it is a calculated risk – that the savings might be real but that nobody knows yet how long today’s technologies will last, and that tomorrow’s technology will be even more reliable, then I’d say you are ready to go LED!

    • #133265
      Richard Kerschner
      Participant

      Even though I am quite a fan of the use of retrofit LED’s in various museum applications,I recommended florescent lights for the storage area mainly because the lights will most likely be on for short periods of time each day and it would take forever to justify the high cost of LED’s vs. the energy savings. In other words, the payback in energy savings would most likely be well beyond the 7-year guideline that most energy consultants recommend.

      As usual, Dale makes very good points about how long the LED’s may (or may not) last and the color shifts that can occur. As some installations are reaching 10,000 hours, color shifts are being noticed. All retrofit LED’s are certainly not created equal in respect light output or color shift. We installed over 1000 retrofit LED’s in our historic houses and galleries after extensive testing because we liked the way the artifacts looked under the LED lights and because our State energy efficiency utility gave us a full rebate on the cost of the LED’s. Had we been required to purchase the LED’s at full price, pack-back in energy cost savings would been close to 10 years and we would not have invested the money at that stage of LED development two years ago. We are observing our LED’s, measuring light output and observing for color shift. We have not experienced any problems yet with our two different brands of bulbs, but they have only been lit for 2500 hours. I view this as a good opportunity to test this technology on someone else’s dime and will share the results as they come in.

    • #133264

      Rick, “Brilliant” observations and comments, as always! The Shelburne is THE place we are all watching to see how very high quality LED’s perform. And your point about ROI is an important one. Fluorescent lamps certainly win the race on return on investment in a storage area where lights are generally off. It’s easy to control UV with tube shields, they are cheap, quickly replaced and efficient. Hard to beat.

      That said, I’ll play devils’ advocate for LED’s for a couple of other reasons:
      * Fluorescent tubes of ANY color temperature are strictly a discontinuous source. The spectral distribution curves (SPD – see above) for fluorescent lamps are essentially deep valleys of no visible light with occasional very steep peaks of tons of visible violet (436 nm), green (547 nm), yellowish green (575 nm) and orange (625 nm).

      * That means that fluorescent light can only reflect violet, green, yellow and orange light off your collections in storage. Your brain will have to (and does) guess about the colors on object surfaces that are missing from the fluorescent output.

      * If your collections staff typically uses collections storage to initially study and examine works to avoid handling and transporting them to better lit study areas (ours do almost exclusively) then I would argue that the better spectral output of high quality LED sources – the LSI LumeLEX 2040-C3M2-6S: LED – 3000K – 96.00 CRI by Xicato for example – will give FAR more accurate visual detail and color, and replicate exhibition lighting much better than any fluorescent.

      * The LED’s will just cost a bundle and be VERY slow on the ROI.

      * Another choice for storage areas, again discontinuous but FAR less so than fluorescent lights, are metal-halide gas discharge lamps or HMI or metal halide lamps. Like fluorescent lamps, these must also have UV filters, but their spectral distribution curve is far more inclusive and they are far more efficient than TH (tungsten-halogen) lamps!

      * To compare evenly matched SPD output curves of incandescent, halogens, LEDs, Metal Halides and fluorescent light sources, go to the National Gallery, London’s Museum Lighting Spectral Power Distribution website: http://research.ng-london.org.uk/scientific/spd/ . There you can learn about SPD’s and compare the spectral output of light sources you are considering.

    • #133263
      Jay
      Member

      Thanks very much for all of the feedback and suggestions. It is extremely helpful.

Viewing 9 reply threads
  • The forum ‘C2C Community Archives – 2012 through 2014’ is closed to new topics and replies.