It was a hot day and I had the air conditioning on in the multi storied mixed-use complex, when I got a service call that the fan was out in the elevator. When I got there the fan was indeed out, but the elevator was stiflingly hot. I couldn’t think of what would make it so hot in there.

When the door closed, I realized what the culprit was. It was the fluorescent lighting. The top of my head was getting hot! Well, that got me to do a little bit of thinking, once my head cooled off!

What I learned was that the lights are on all day, all night and all year. Yes, 24/7/365! They never go dark because they are emergency lights. Even in a power outage, there would be battery backup on a portion of the lighting array. I guess the elevator manufacturers learned from the great blackout in New York City back on the 9th of November in 1965 that being stuck in a dark elevator cab for hours would not be pleasant! There are five 40-watt fluorescent bulbs that light the elevator car or cab. There were also two ballasts running these. All these items produce heat above your head. The cab was set up with space for 6 bulbs, but only five were ever installed.

The 40 watt bulbs use 200 watts an hour, 4.8 kilowatts a day, 33.6 kilowatts a week, or 1,747.2 kilowatts a year. At my marginal rate of 8.3 cents per kilowatt-hour that’s $145.02 per year. That’s my baseline, which does not include the power draw from the two ballasts that keep the fluorescent lights getting the power when needed. I’ve seen an estimate for the ballasts that lists 10 watts each. In my example that would be 20 watts per hour or about ten percent the total of the bulbs across the board.

The LED technology for these four-foot tubes is not as advanced as it is for street lighting, but I do know that they run cooler. I chose a 14-watt LED that produced light at 5,000 Kelvin or essentially in the daylight range to replace the 40-watt fluorescent bulbs that were a cool white. The kicker is that the LED produced only 1,800 lumens while the fluorescent emitted 2,400 lumens. The five fluorescent bulbs totaled 12,000 lumens when newly installed. It would take seven LED bulbs to equal the output, however there was only room for six. One of the spaces for the four-foot bulbs was never used. An LED array does not need a ballast though, so there’s that ten percent extra savings.

That’s all well and good, but what is the code? The latest elevator lighting requirements are for 5-foot candles in regular lighting and 0.4 foot candles in emergency lighting. I may be wrong, but I added these two together to come up with 5.4-foot candles. The cab measures six foot by eight foot. So the number of foot candles required is 6 times 8 times 5.4, which equals 259.2 total foot candles and is then multiplied by 10 for conversion to lumens to equal 2,592 lumens. Two bulbs would be sufficient. It didn’t matter if they were fluorescent or LED, just two bulbs!

The only reason why there might have to have been 5 fluorescent bulbs in this cab that I can think of is that the fluorescent bulbs don’t last that long so you’d replace half the bulbs each time they commenced flickering. Likewise, to protect against falling below the minimum acceptable lighting level, just three LED bulbs would be enough under the proviso that as soon as one failed, it would have to be replaced.

The LED conversion electrical consumption would thus be for three 14-watt bulbs. That would be 42 watts per hour, 504 watts per day, 3.5 kilowatts per week, or 183.5 kilowatts per year. My yearly cost would be reduced to $15.23 from $145.02. That doesn’t include the savings from not running the ballasts, or even the savings from running the air conditioning less frequently. Then there’s also the fan that gets the cool air into the elevator cab that had failed and made me notice what was out of sight and out of mind in the first place!

My costs were $16 per bulb, because the bulbs were directly wired and bypassed the ballasts, and two hours for the technician at $50 each. My costs might not be representative of what your costs might be. My total was $148. Calculated as a payback period, that would be a little under one year and one month. Work well worth doing.

My local YESCO Sign representative, Rick Nichols, helped design and install this system. He had confirmed that it would literally cost just a handful of dollars a year to operate should I make the switch. You can call his YESCO Sign office at 1-603-238-6988. His website is: http://www.yesco.com/concordnh/ . Please use this link for his email: This email address is being protected from spambots. You need JavaScript enabled to view it. . You may also want to copy his office manager and account executive, Elizabeth Baker does his scheduling. Her email is: This email address is being protected from spambots. You need JavaScript enabled to view it. . I should add that Mr. Nichols did the conversion on a Sunday while the building was not occupied. If he can do that for me, I’m sure he can get the job done for you!