Yes, this is broadly in line with my observations of the market. LED lamps have a great future in their own right, but they do not fare well as plug-in replacements.  Mercury fluorescent tubes have been around for a while now, but still compare favourably on efficiency and can be classed as "energy saving". (Oldie but goody!  Like lead-acid batteries, which we have discussed recently)


I was considering LED tubes as plug-in replacement for mercury-fluorescent for various places but found that a 1·5 m (5 ft) LED tube has a claimed output of circa 3 000 lumens (about the same as a 1·2 m (4 ft) mercury fluorescent in fact) against circa 4 500 for a mercury fluorescent 58 W tube. So if you do a straight replacement to LED tube, you will certainly save electricity but I think you will be disappointed with the light output. The LED tubes will be more directional in light output but I don't think this will compensate.


Fluorescent tube light output does drop off as the tube ages. You could simply replace the tubes with new mercury fluorescent. Or even replace the fittings with 1·5 m (5 ft) ones. The fittings usually have mercury fluorescent tube included, so you would enjoy lots of light.


Digressing slightly, I have been making some similar comparisons of MR16 halogen reflector lamps, and their LED GU10 plug-in replacements. Watch this space!

Over the past 3 years I have changed over all by fluorescent ceiling mounted fixtures 4 ft x 2 ft (2 or 4 tube) and 2 ft x 2 ft (U tube) over to LED's.

I use magnetic strip LED's with drivers at 3,000 K (color).


One rips out the old lamps, sockets and ballast. The LED strips and driver are magnetically held to the existing metal fixture.


Connect the power and replace the plastic cover lens on the fixture and one is finished.


Takes about 10 minutes max.


Peter Brooks MIET Palm Bay Florida USA

Thank you for your thoughts. Having also read the thread in the Wiring Regs Forum I decided to take the easy route and bought two new fluorescent tubes and fitted them. They are subjectively much brighter, my camera estimates twice as bright (half the shutter speed).


Best regards


Roger

Just for the record there were three reasons why I changed all my fixtures over to LED's.


Some of my fixtures were the old T12 tubes (large diameter) which I expect will be phased out fairly soon.

Second was the improved efficiency and reduced power consumption 

Third was the part of my overall plan to harden the house.The long life of LED (15-20 years)  hopefully will eliminate the need to climb ladders as one progresses towards 90.


Peter Brooks MIET

Palm Bay, Florida USA 

Peter Brooks:

Just for the record there were three reasons why I changed all my fixtures over to LED's.


Some of my fixtures were the old T12 tubes (large diameter) which I expect will be phased out fairly soon.

Second was the improved efficiency and reduced power consumption 

Third was the part of my overall plan to harden the house.The long life of LED (15-20 years)  hopefully will eliminate the need to climb ladders as one progresses towards 90.


Peter Brooks MIET

Palm Bay, Florida USA 

 

Just so long as you buy the right ones.  I have seen lifetimes of up to 100 000 hours quoted for LEDS.  But that assumes they are adequately cooled.  It also helps if the driver wasn't sourced from the cheapest supplier.  It's not a lot of use having long life LEDs if the driver doesn't last beyond the first power spike on the supply.

Hello Simon:


You are absolutely correct concerning watching for defective drivers and LED chips.


Before installing I burn-in the complete system for 24 hours using my wife's baking pans as heat sinks (using the magnetic attachment).


I have seen a number of defective LED surface mounted lighting fixtures displayed at our local big box hardware stores.


My LED drivers are those used for portable computers covering both supplies voltages from 100 to about 250 AC volts at 50/60 HZ. In the US we use 110 volts AC.


Thus a loss of the neutral still meets the input voltage requirement.


Regarding lightening induced power spikes 2 KV+ our house it generally protected by our adjacent overhead HV power lines.


Peter Brooks MIET

Palm Bay Florida USA

Nice to hear the end of the story. Peter Brooks's idea of using LED strips is an interesting one, but I think it is more appropriate to rectangular flat fittings, rather than individual fluorescent fittings, as in Roger Bryant's case. However, the more ideas, the merrier!

Hello Denis:


This is not an advert, but if you want to see what range of LED lights are available here in the US go to the URL www.eledlights.com


There are also links to videos showing installations. 


Peter Brooks MIET

Palm Bay Florida USA

I took a look - that's quite an impressive range, Peter! I note that the LUX range of LED plug-in replacement tubes can match the lumen output of the tubes they replace.