Carport work light LED upgrade

[-Spike-]

I also installed the LED light tubes, and geeked out just a bit on them. I did some measuring and comparing, on energy consumption and light output. I used an inductive amp meter and an app that measures lux. The lux reading may or may not be accurate, but it is useful as a relative measurement. I measured lux from an approximate distance of 4 feet below the fixtures.

The fixtures with original ballasts and two 40 watt T12 Alto fluorescent tubes drew about .8 amps each and read ~220 on the lux meter.

The fixtures with upgraded electronic ballasts and the same tubes (even the same age; I did not replace the tubes when I changed out the ballasts) measured .6 amps and ~420 lux. I was pretty impressed with the increased light when I originally changed these ballasts 3 years ago.

The fixtures with no ballasts and Barrina 22 watt LED tubes draw .3 amps and measure 740+ lux.

By my calculations the LED tubes, rated at 22 watts, are actually only drawing a little over 18 watts each (122 volts x .3 amps = 36.6 watts /2 bulbs = 18.3 watts). That's probably explained by voltage differences or something. I'm not upset- the light output is more than sufficient.

All of the light from the tubes is directed down from the diodes, rather than all around with fluorescent tubes, which probably explains a lot of the higher perceived light output. The light is evenly distributed below the fixtures, no spots. The wall cabinets against the ceiling are well lit.

Bottom line- much less than half the energy used and over triple the light output of the original ballasts, and nearly double compared to the electronic ballasts. I'm quite happy! My shop looks like a laboratory instead of a cave.

The fluorescent bulbs were cool white (4100K) while these LED's are 6000K. I have always avoided 'white' light bulbs, but after seeing these in action I prefer the whiter color for working. They would drive me crazy in a kitchen or other non-clinical environment- the light is stark and harsh, but it brings out details and adds contrast.

Wiring was easy- neutral (white) wire goes to all of the wires at one end of the fixture, and hot (black, usually) goes to all the wires at the other end. The instructions say that the ends of the bulbs have stickers saying which end goes where, but mine did not. Also, it didn't make a difference- I installed them both ways without issue. I marked all the fixtures in case I get replacement tubes that do care about polarity, and I noted that they didn't have ballasts- LED only. That way if someone buys the house they aren't surprised.

One other note- the lenses have a clear protective tape on them. I didn't see it at first. It is pretty clear, but it does defract the light a little. I was amazed at how clear the lenses are when I took the tape off. I went back to take off the tape from the ones that got by me and found that they are much more difficult to get off when warm. Easy when cold.

I installed 36 tubes, and didn't find so much as one diode bad, no shipping damage, no problems. There are some reviews on Amazon mentioning shipping damage. There are caps on the exposed contact pins which should protect them, and may have been added after complaints came in.

Also, for those wondering about tube types, these are T8 tubes, which denotes the diameter. The contact pins are exactly the same as my original T12's, and they fit perfectly.

So, if you already have fluorescent light fixtures, this is a pretty sweet mod.

 

[GWcruiser]

Interesting data; Always wondered just how much difference an old 60Hz LF transformer vs electronic HF ballast makes.

As for measurements, one thing to keep in mind is power factor (voltage/phase/current relationship when trying to measure AC power). Not all things are equal with non-linear loads like ballasts and DC switching supplies. Specialized power meters or dual channel scopes with math functions are usually best. Actual AC power can be much different than what Volts * Amps shows.

Area of brightness figures into the overall efficiency, measuring five or six points is best for each light condition: four corners and one or two points in the middle gives a fair idea of how even the light is or if falloff is different between lamps. And different colors (light spectrum) can really mess with "photo" based light meters because of the filter applied to mimic the human eye response; probably why the 6k LED's measure so much brighter than 4k flourescents.

lol - too many years of metrology engineering showing here.

 

[-Spike-]

All I can say is the shop is lit up like Fenway Park, so I don't think the light meter (phone) was fooled too badly by the color change. Regardless, I'm very happy with the results. As far as power consumption, all that matters to me is amp draw- that's what I pay for.

 

[GWcruiser]

Bright is always better where you are working; I prefer the daylight white LED for most of the work lights I use since they help my color vision.

The measurement issue is complex, but real. Though the LEDs not having ballasts is probably saving you 30 to 50% right there, plus they are inherently more efficient creating photons than filaments and fluorescent tubes... lol. So its a win. I updated a bunch of halogen and CFL lamps around my house for the same reason: in kitchen & baths where lights seem to be left on too long, why have 6 50w Halogen lamps burning when 6 4w LEDs get the same job done.

 

[2fpower]

FYI, I had one bulb go bad on about 1/3 of the LED surface. Emailed Barrina, and they mailed a replacement that day, no questions asked.

Very happy with this mod.....