Lighting advice

[Martin KyteParticipant @martinkyte99762]

Posted by Mark Rand on 29/08/2022 09:48:06:

Not a lighting expert here again .

 

So, as I stated, Fluorescent tubes and LED lights produce pretty much the same amount of light per wat.

Custom designed LED lights get away with lower power by being directional. So I stick by my claim of equality, since I don't want a dark ceiling or dark line along the top of the walls.

I have a stock of 22W T8 LED 'replacement' tubes. I put them in last time I decided to renew the fluorescents. Took them all out again because they were so dim and replaced with new fluorescents. I've got enough fluorescent tubes in stock for one more cycle of change, then I'll have to invest serious money (£600 at current prices) to replace the current fittings with low profile LED panels. Hopefully the CRI will have improved slightly over the few years that'll take.

 

So back to the Chris Murphy:- I retract my recommendation for fluorescent lamps, but go for more wattage than you think you'll need.

Edited By Mark Rand on 29/08/2022 09:52:18

"So, as I stated, Fluorescent tubes and LED lights produce pretty much the same amount of light per wat."

Not sure where you get that from. Flourescents are around 50 to 100 lumens per watt and LEDs come in at 130 lumens per watt. Thats before you consider the directionality. Flourescent tubes are omnidirectional and LED's in general are 110 degree giving a gain of approximately 3.3. So when you take that into consideration the figure for LEDs rises to 429 lumens per watt so roughly 4 time the light output for the same power consumption.

Also not sure where you get your £600 for the panels from unless you are replacing every fitting? They are available for under £20 each. Here is my kitchen with 3 (in home made housings). Pleanty of light for my kitchen. I would put more in a workshop and be intelligent with the placing.

regards Martin

 

 

Edited By Martin Kyte on 29/08/2022 13:33:47

[Mark RandParticipant @markrand96270]

Lumens are a measure of light output not brightness. You might change the brightness in part of the area with directional lights, but you aren't emitting any more light.

New fluorescents produce 100lm/W. Clapped out T12 fluorescents that had been in service for a few decades would produce 50lm/W by the time you replaced them (30 years ago for most folk).

Commercial fluorescent light fittings have reflective interiors, so the unidirectional light from the tube is pointed in the directions that it is needed.

So LED and fluorescent are equivalent. The reason for banning them isn't efficiency, it's because they contain 20-40mg of mercury per tube

The £600 is based on 14 3450lm 300mm x 1200mm flat panels at £38.88 each to replace the existing 14 36W HF ballasted flouorescent fittings in a 300m^2 shed with 3.2m high ceiling.

Edited By Mark Rand on 29/08/2022 15:50:17

[Martin KyteParticipant @martinkyte99762]

As I said "thats before you consider directionality" 130 is larger than 100 so watt for watt you get more light output from you LED's.

regards Martin

[Mark RandParticipant @markrand96270]

130 != 429

30% improvement is a poor payback for £600.

Going away now.

[Clive FosterParticipant @clivefoster55965]

When I built my "new" workshop I used 8 twin "naked tube" 5 ft fluorescent fittings. No diffuser or reflector, painted the ceiling and walls brilliant white so the illumination was clear and shadow free. Fittings spaced so each primarily lit an 8 ft square bay. Obviously there was considerable overlap between the contributions of each tube.

Replaced each twin fitting with one daylight white 600 x 600 panel, presumably 40W, after getting fed up with the relatively short life of modern tubes even though its only a 1/4 mile walk to the local electrical shop who keep name brand tubes in stock. Average seemed to be 5 or 6 years per tube.

Workshop is a lot brighter and much nicer to work in. LED CRI is, as Mark says, pretty pants so the light is harsh but edge definition is good. At 68 my eyes need all the help they can get. There is no doubt that the daylight white LEDs are subjectively far brighter than the cool white and warm white breed.

Clive

[Mike HurleyParticipant @mikehurley60381]

One of my 2 T8 led tubes failed a few weeks ago (after about 18 months – so much for the super extended lives of LEDs!). When looking for a replacement, I noticed that the 2 local go-to hardware / electrical chains (SFX & TS) seemed to stock a much smaller range of sizes and powers than they did when I bought mine last.

Are 'tubes' a dying breed in repect of the thousand and one other lighting options on the market?

[Roger BestParticipant @rogerbest89007]

I am sure there is some consolidation in the market, personally I detest that every fitting I desire is Edison Screw and not Bayonet Cap.

Its worth remembering that for detailed work you need about 4 times the brightness (lumens per area) than you can get away with, and your iris will close so it doesn't feel that much brighter, however your focus will improve and you will get less eye strain. Think of it as modest expense to future-proof your eyes.

I have double LED tubes over all of my benches and machines and still use directional task lighting because it still makes a terrific difference.

[Mark RandParticipant @markrand96270]

Update on this thread:-

I recently had an HF ballast go bad on one of the 36W 4′ light fittings in the shed. I looked around to see if I could find any LED tubes which were better than the ones I had tried before. I found the Sylvania Superier range and chose this one to try out. Fitted it this morning and am very pleased with the result. It’s comparable with brand new fluorescent tubes but uses half as much electricity (it has a 220° beam angle and very efficient LEDs). Retrofitting these to all of the fittings in the shed could save 250W, which is significant. They are definitely not cheap but payback would be after 2,700 hours, including one round of replacement Fluorescent tubes in that period. I think that I’ll invest in another 13 to make up a full shed’s worth. 😀

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