Shop Lighting Commentary

cathead

CATWERKS LTD
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Feb 7, 2013
Messages
2,481
With the influx of the new LED lighting, I expect some of you have already added some of the
new high efficiency lights. My shop has mostly 4 foot fluorescent lights so will be slowly
phasing them out in favor of the new more efficient and environmently friendly lighting.
I just bought a test under counter light by Feit and installed it over my kitchen stove. It
really puts out the light for it's small current draw. I see there are 4 foot LED shop lights
available now and wondering if any of you have installed and used them. Most of these
shop lights seem pretty expensive to me so decided to procrastinate a bit and take my
time in the change over. Another factor is the fact that all my 4 foot fluorescent lights
are hard wired so would probably have to junk them and replace with the new. I have
not seen any LED 4 foot replacement bulbs but just replacing the bulbs would be easy.
I doubt such a thing exists though as the fluorescents run on very high voltage and the
LED operates on low voltage. I'm curious to know your experiences.
 
I got 10 of the 4 foot led florescent replacement bulbs about 6 months ago. They are great. Wish I had more 4 foot fixtures. I have more 8 footers and am anxiously waiting for 8 foot led bulbs. They are just starting to show up on ebay, but the price is still pretty high.
The local costco store has snap on 25 watt work lights. Incredibly bright. I put 3 of them in the rafters in on of my shops and now use them (75 watts) instead of turning on my 3 eight foot HO florescents (660 watts)
 
When I did a complete remodel of our kitchen some nine years ago, I elected to go with LED lighting. It was cutting edge technology at the thime. Although they were more efficient at the time than halogen, they had ways to go.

Today, LED is arguably the most efficient lighting available, running in the 140 lumen/watt range. Often, efficiency is rated in terms of efficacy. LED lighting is fundamentally different than other lighting in that it projects the light in one direction, typically a 120 degree cone, as opposed to nearly 360 degree radiation of incandescent and fluorescent lights. Back light has to be reflected to be useful in most case and there are losses associated with that. Because the LED's provide a greater percentage of useful light, their output seems higher than it actually is. They use efficacy to describe the useful light output. I used warm white LED's, (~3000K) for ambiance but the cool white are the most efficient.

LED's are low voltage DC devices and regular household current has to be transformed. Standard transformers have energy losses associated with them which reduces overall efficiency. Additionally, LED's have to have current limitation provided to prevent thermal runaway and self destruction. This is most simply done by placing a ballast resistor in series with an LED string. These resistors transform electrical energy into heat, again reducing the overall efficiency. Great strides have been made in the driver circuitry for them. Modern LED drivers usually use some sort of switching technology to drive the LED's. This typically runs more efficiently than other forms.

I always look for light output on any LED I buy. Don't trust high intensity claims unless they are backed up by specs. Commercial LED lighting providers use two metrics to describe their product; equivalent light output and actual output. Equivalent output is usually compared to a standard incandescent bulb (40 watt, 60 watt). Fluorescent replacements usually give actual lumen output. T12 fluorescent lamps typically have a an output of around 3500 lumens for a 40 watt lamp. If you want an equivalent amount of light in your replacement fixture, you should be looking at this as a guideline.

For the more adventurous, there is LED strip lighting. I used this on our front porch instead of fluorescent lamps. A five meter strip replaced four fluorescents. My wife insisted that I put a dimmier on them because they were too bright. They are found in strips running up to 5 meters long. They have a self adhesive backing and run on 12 volts dc with built-in driver circuitry. They can be cut at intervals of 3 LED's, usually about 1-1/2" and the can be connected together to make longer runs. I mount them on an aluminum backing, 1/8 x 2" flat or 1/2" aluminum channel (sold as plywood edging at the local DIY). It helps with heat sinking which increases light output and service life and should replacement be necessary, makes for easier work. Replacement of defective LED's, should that happen is done by cutting out the bank(s) of three and solderingng the replacement. This is something I have yet to do. I provide the 12 volt dc power with high efficiency switching power supplies which are quite economical now.

LED Supply sells drop in replacements for 4' fluorescent's. Environmental Lights also sells commercial fixtures for area lighting. Both are on-line and companies I have had excellent service from.

Bottom line: LED lighting is more efficient but it is still quite pricey compared to other forms. I have fluorescent lighting in my shop and am not contemplating replacement of same at this time because the incremental savings in electricity for LED replacements is not that great yet. I have replaced almost all incandescent lighting however and will use LED lighting for all new projects. The LED technology and the driver technology are both making great advances. Costs will come down in the near future, due to improved technology and volume manufacturing. It may be advisable to wait a few years to be able to take advantage of forthcoming advances.

A factoid: Not many people realize that white LED's are fluorescent devices. They replace the mercury vapor excitation with blue LED excitation. Much off the efficiency gains in recent years had to do with developing better phosphors.
 
When I did a complete remodel of our kitchen some nine years ago, I elected to go with LED lighting. It was cutting edge technology at the thime. Although they were more efficient at the time than halogen, they had ways to go.

Today, LED is arguably the most efficient lighting available, running in the 140 lumen/watt range. Often, efficiency is rated in terms of efficacy. LED lighting is fundamentally different than other lighting in that it projects the light in one direction, typically a 120 degree cone, as opposed to nearly 360 degree radiation of incandescent and fluorescent lights. Back light has to be reflected to be useful in most case and there are losses associated with that. Because the LED's provide a greater percentage of useful light, their output seems higher than it actually is. They use efficacy to describe the useful light output. I used warm white LED's, (~3000K) for ambiance but the cool white are the most efficient.

LED's are low voltage DC devices and regular household current has to be transformed. Standard transformers have energy losses associated with them which reduces overall efficiency. Additionally, LED's have to have current limitation provided to prevent thermal runaway and self destruction. This is most simply done by placing a ballast resistor in series with an LED string. These resistors transform electrical energy into heat, again reducing the overall efficiency. Great strides have been made in the driver circuitry for them. Modern LED drivers usually use some sort of switching technology to drive the LED's. This typically runs more efficiently than other forms.

I always look for light output on any LED I buy. Don't trust high intensity claims unless they are backed up by specs. Commercial LED lighting providers use two metrics to describe their product; equivalent light output and actual output. Equivalent output is usually compared to a standard incandescent bulb (40 watt, 60 watt). Fluorescent replacements usually give actual lumen output. T12 fluorescent lamps typically have a an output of around 3500 lumens for a 40 watt lamp. If you want an equivalent amount of light in your replacement fixture, you should be looking at this as a guideline.

For the more adventurous, there is LED strip lighting. I used this on our front porch instead of fluorescent lamps. A five meter strip replaced four fluorescents. My wife insisted that I put a dimmier on them because they were too bright. They are found in strips running up to 5 meters long. They have a self adhesive backing and run on 12 volts dc with built-in driver circuitry. They can be cut at intervals of 3 LED's, usually about 1-1/2" and the can be connected together to make longer runs. I mount them on an aluminum backing, 1/8 x 2" flat or 1/2" aluminum channel (sold as plywood edging at the local DIY). It helps with heat sinking which increases light output and service life and should replacement be necessary, makes for easier work. Replacement of defective LED's, should that happen is done by cutting out the bank(s) of three and solderingng the replacement. This is something I have yet to do. I provide the 12 volt dc power with high efficiency switching power supplies which are quite economical now.

LED Supply sells drop in replacements for 4' fluorescent's. Environmental Lights also sells commercial fixtures for area lighting. Both are on-line and companies I have had excellent service from.

Bottom line: LED lighting is more efficient but it is still quite pricey compared to other forms. I have fluorescent lighting in my shop and am not contemplating replacement of same at this time because the incremental savings in electricity for LED replacements is not that great yet. I have replaced almost all incandescent lighting however and will use LED lighting for all new projects. The LED technology and the driver technology are both making great advances. Costs will come down in the near future, due to improved technology and volume manufacturing. It may be advisable to wait a few years to be able to take advantage of forthcoming advances.

A factoid: Not many people realize that white LED's are fluorescent devices. They replace the mercury vapor excitation with blue LED excitation. Much off the efficiency gains in recent years had to do with developing better phosphors.
RJS,

Yes, I see that you can get 4 foot LED lights that fit in the fluorescent units I have. The fluorescent transformers
are some thousands of volts I believe so do they transform it down again and then feed the LED strip? It would
be more efficient if one started with 120 volts rather than the high voltage or does one have to rewire the fixture
and remove the ballasts? I would think that would be the sensible thing to do if I were building these bulbs myself...
If one has to go through two transformers to get to the voltage the LED needs, it wouldn't be the most efficient.
 
The 4 foot leds I put in my florescents are rated for 85-277 volts. Supposedly you can leave the ballast in...I removed them from my fixtures...If your going for efficiency...no use powering the unneeded ballast.
 
RJS,

Yes, I see that you can get 4 foot LED lights that fit in the fluorescent units I have. The fluorescent transformers
are some thousands of volts I believe so do they transform it down again and then feed the LED strip? It would
be more efficient if one started with 120 volts rather than the high voltage or does one have to rewire the fixture
and remove the ballasts? I would think that would be the sensible thing to do if I were building these bulbs myself...
If one has to go through two transformers to get to the voltage the LED needs, it wouldn't be the most efficient.
I don't believe that the old ballasts are thousands of volts. Their function is to limit the current in the tube. The starting circuit heats a filament to vaporize the mercury and start current flow in the tube. It switches out when the tube fires. I haven't measured actual voltage supplied to the tube so I can't say anything definitive about it. HF lights may be a different kettle of fish. They do not use the starter circuit. I have never measured voltage on those either. From the description of the LED Supply lamp, they give about a 30% increase in efficiency over the fluorescent fixture. I would expect the fluorescent manufacturers would spec. overall efficiency as would concerned energy conservationists. If that is the case. the quoted values are in line with what I would expect. (fluorescent's have about an 80-90lumen/watt efficiency, cool white LED's about 100-140 lumen/watt). I would expect that the drop-in replacements have a switching type driver and are able to accommodate a fairly wide range of voltages. I would call them up and ask. They have very knowledgeable tech support.

If I were going to build my own, I would use the 12 volt strips instead. You can use the fixture as the base. Strip out the guts of the old fluorescent fixture. Use an aluminum strip for mounting. You can also mount directly to the fixture but the impairs any future maintenance. Purchase a suitable switching power supply. DigiKey right in your back yard is a good source is Jameco in California. We machinsts are very capable of making any required mountings, adapters, etc. I did bounce lighting in our kitchen with a double row of these strip lights and it does an excellent job.

For alternatives, there are some interesting LED's out there. I have a couple of CXA 1310's that will put out almost 2000 lumens from a single 6mm disk. The cost was reasonable, under $10 as I recall. I purchased a LuxDrive 700 ma Flexblock for driving them. In terms of $/lumen, probably about as good as you will find. We have the automotive headlighting technology to thank for that. The big problem with these is that they are blindingly bright. For area lighting, you would need to design some sort of diffuser.

Bob
 
One item that should be in every shop is a battery backed emergency light. They aren't expensive, and easy to install. My shop has one small window, and at night it's pitch black in there. Being able to see if the power goes out is important for safety.
 
I recently replaced all the T12 fluorescent tubes in my shop with LEDs. All of my fixtures were hardwired and the magnetic ballasts were starting to fail after some 30-40 years. The retrofit was pretty simple -- just bypass the ballast (you can remove the ballast or leave it in, but no power goes to it) and wire the tombstones directly. It took about 5-10 minutes per fixture. The light is great and the best part is no more annoying buzzing from the dying ballasts.

One thing to note is that your tombstones have to be the non-shunted variety. I think most of the older T12 fixtures are this type, but if you're replacing T8 bulbs, you may have to replace the tombstones as well. They aren't very expensive though.
 
OK SUPER! AND they would start instantly if the shop was cold I would surmise. So where would be a good source for
some 4 foot LED replacements?
 
They're not affected by temperature, but they do take a second to turn on. I'm used to it now.

I bought mine on sale at 1000bulbs.com, but the ones I bought are no longer in stock. Amazon sells them as well.
 
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