Over a year ago, I decided to give LED’s a whirl and the LED's decided to give me a headache. I decided that I could not make a verdict on the purchase until a year had passed. It's been over a year, so here goes:
First thing, I did not install them for interior lighting, but for exterior night-time lighting only. I’m sure many of you are aware that LED’s are more popular for exterior lighting than they are indoors. In my opinion, exterior lighting is one of the best places to get LEED points because of the undisputed energy savings, plus LED’s can easily meet the lighting pollution reduction SSc8.
In any, case - why’d I update to outdoor LED’s? Naturally, I am energy conscious, but the main reason is because the incandescents were suffering very short lifespans and there was difficulty when changing bulbs in the outdoor fixture. I'd have said, "Hell with it", but the lighting is required by all residences in my neighborhood.The incandescents were averaging a lifespan of less than 1 month. I didn't know why at first but I finally realized that the wind was rattling the fixture, breaking the filaments on my “long-life” candelabra incandescents which were about $1 each.
So, I ordered a 3 pack of candelabra LED’s which I got for $25 on amazon. I installed them and had the classic problem associated with LED’s. The candelabra fitting was slightly too short. At this point, I was pretty annoyed but I had heard of candelabra extensions. I ordered some from bulbs.com. They were $1.59 each and shipping was around $10, so after tax, I had another $15 into it. However, they did work. I installed the three LED’s and I noticed on the first night that my exterior lighting was way brighter than my neighbors. I checked the lumen ratings on the 40 watt replacement LED’s and saw that they were rated at 300 lumens. The 25 watt long-life incandescents were only 200 lumens. Thus, I removed one of the LED’s, and that made my lights look nearly identical to everyone else’s.
Installed them on Thanksgiving 2012. Averaging 12.1 hours per night of lighting, since they are controlled by a photocell, the lights just hit 5,000 hours.
What’s the savings?
The great thing about exterior lighting is that it is the simplest energy saving calculation you can have.
5000 hours * 4.8 watts*2/1000 * $.13/kW-hr = $6.24
5000 hours* 25 watts*3/1000*$.13/kW-hr = $48.75
Cost of the bulbs for the 1st year:
= $40 for the LEDs
= $36 for the incandescents
Thus, in the first 5,000 hours, the bulbs saved me nearly $40, but energy cost aside, the LED’s have saved me a quite few hours of changing bulbs and so far they have reached 5,000 hours and counting.
Now I understand why ASHRAE 90.1-2007 added “Addendum L”, which lowers the amount of exterior lighting you are allowed in the baseline building. I’m guessing that LED’s are gaining outdoor popularity? What do you think?
Bob Fassbender graduated from the University of Wisconsin - Madison with a degree in Chemical-Engineering. Following graduation, he spent 3 years working as a Marketing Engineer for Trane C.D.S. In the C.D.S. group, Bob developed and supported design and analysis software, primarily TRACE 700™. In addition to his development work, Bob also traveled around the country as a TRACE 700™ and System Analyzer™ instructor. Bob is also an experienced user with eQUEST energy modeling software. Today, Bob continues training and energy modeling as a LEED accredited professional (with a focus on LEED EA credit 1).
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