Replacing Halogen Floodlight With Leds?

[Gaz k]

Hi all.

 I have a standard 500W halogen floodlight mounted under the eves of my 2 story property. I am getting fed up with regularly replacing the blown bulb or the fitting as the terminals burn away due to bad connection with the bulb. The unit is powered via a standard 13A plug in the loft via a remote control stitch so that it can be turned on/off from downstairs.

 I have considered replacing the unit with a LED floodlight but  when I tried a couple of 50W LED floodlights with the wide spread of light from such units at the height that they are mounted, I am lighting the gardens of the properties on both sides and also the A road that runs at the bottom of my garden whilst failing to get enough light on my property.

 Plan B is to fit a 12V 240w transformer in the loft powered as above, and to use the original  twin and earth cable (that is buried in the wall) to feed the 12v supply to 4 x 48w Cree LED vehicle spotlights which should produce considerably more light than the original halogen unit whilst being more reliable and also more directional than a standard LED floodlight.

could anyone help with the following queries-

Is this a reasonable idea or will I be breaking any regulations?

Given that there will be losses in the transformer, would this be more efficient than the existing light?

Would the input surge cause any issues?

 Thanks in advance for any replies.

 

[Andy™]

at 12v, the current will be 20 times what it would be at 240, so youre likely to have volt drop issues with the existing wiring. thats if you dont melt it

easiest option would be an LED flood with a small beam angle...

 

[Gaz k]

easiest option would be an LED flood with a small beam angle...

Could you point me in the direction of such a unit as a quick search dosen't produce any results

 

[Doc Hudson]

Don't have a light mounted so high. Use a lower fixing height.

Doc H.

 

[Gaz k]

Don't have a light mounted so high. Use a lower fixing height.

Doc H.

That plan C, but with no option to put lights at the other end of the garden the lighting would be poor.

 

[Doc Hudson]

That plan C, but with no option to put lights at the other end of the garden the lighting would be poor.

Unless your house wall leans at an angle toward the far end of the garden I think that is technically impossible. Light intensity reduces the further away you put the source of the light. Generally moving the source higher up the wall is moving it a greater distance from the end of the garden. Plus mounted lower down, you waste less of the light you produce by illuminating the rest of the neighborhood when fixed under the eaves.

Doc H.

 

[Gaz k]

Unless your house wall leans at an angle toward the far end of the garden I think that is technically impossible. Light intensity reduces the further away you put the source of the light. Generally moving the source higher up the wall is moving it a greater distance from the end of the garden. Plus you waste less of the light you produce by illuminating the rest of the neighborhood.

Doc H.

I take your point regarding distance and height, however for example, the sun is giving out the same amount of light just before it dips below the horizon as when it is directly overhead, yet due to the angle of the light and the area it is covering, it is much darker. I would argue that the lamp is more effective when higher up. The floodlights at you local stadium, I'l wager are as high as possible(although there is more than one)

 

[Doc Hudson]

The sun and sports ground floodlights are a very different ball game to the average domestic single lamp lighting application. There are equations for calculating light intensity proportional to the distance from the source. However you care to wager, science tells us the intensity is less the further away you position the lamp. http://www.portraitlighting.net/inversesquare_law.htm  The objective is to maximise the light onto your target area. Not scatter it wide over the surrounding area. Also another option is two smaller lamps lower down which can be more effective than one larger lamp higher up. Two light sources reduce issues of your own shadow darkening what you are trying to see. 

Doc H.

 

[pewter]

Is extra low voltage stuff now notifiable for part-p building regulations.

4x48W Cree LEDs, Wow. That would be very powerful.

 

[Gaz k]

4x48W Cree LEDs, Wow. That would be very powerful.

 Each spotlight is made up of 16x3watt cree LEDS and according to the specs produces about 3500lm

 

[binky]

might not do what you want, the importnt criteria is the beam angle, and it sounds like you need something narrowish with a lens that projects the light forward. If you go ahead with several lights a combination of beam angles might work ie wide beam for near the house, narrow beam for range and not dazzling the neighbours.

 

[Gaz k]

might not do what you want, the importnt criteria is the beam angle, and it sounds like you need something narrowish with a lens that projects the light forward. If you go ahead with several lights a combination of beam angles might work ie wide beam for near the house, narrow beam for range and not dazzling the neighbours.

agreed. I was planning to use a combination of spot and flood beam.I could use 2x 96w lamps but would have less ability to direct the light.

 

[Richard-the-Ninth]

Why could you not have more lights lower down, closer to where they are needed?

 

[Gaz k]

Why could you not have more lights lower down, closer to where they are needed?

That has already been suggested by DH ,a few posts back and is an option,I am just exploring other ways of doing whilst keeping the lights where they are. I was trying to avoid more conduit running down the side of the house

 

[Richard-the-Ninth]

Sorry I was not clear enough. I mean 4, 5  or even 6 small lights much lower down. It will not light the neighbours gardens, and you will get a more even light.

 

[Gaz k]

Sorry I was not clear enough. I mean 4, 5  or even 6 small lights much lower down. It will not light the neighbours gardens, and you will get a more even light.

It has been suggested to have a couple of lights lower down on the wall, but would the light be effective at the bottom of the garden, say 20m away from the wall due to the very shallow angle of lighting?

 

[Richard-the-Ninth]

How effective they would depend on the lights you choose and any obstructions, which we can not see on a forum without pictures. I am still suggesting 4,5 or 6 lights lower down and closer to the area you want illuminated. Not just lower down from where the light currently is.

 

[djsammevents]

i have used some LED floodlights and the 50watt LED's are very bright and last a longtime