400w SON replacement

Joined
31 Mar 2006
Messages
20,000
Reaction score
1,381
Location
Leeds
Country
United Kingdom
I’ve got a commercial property which has a car park lit with 400w SON floodlights using a mixture of white and orange lamps.

They have asked me about replacing the existing lights with LED fittings to reduce energy usage and maintenance. The customer is happy for all the new lighting to be 4000k cool white, but would like to keep the existing level of illumination. There are residential properties opposite this building.

I am looking for a bit of guidance as to what wattage of LED fitting would be required to replicate a 400w SON flood, and also if anyone has a recommendation of a make which is good quality in terms of reliability and has a good output pattern so as to not cause too much light pollution on to the nearby properties.
 
Sponsored Links
Joined
20 Aug 2009
Messages
9,351
Reaction score
1,208
Location
Dorset
Country
United Kingdom
Have you considered LED street light fittings mounted on the appropriate wall brackets?
 
Joined
28 Apr 2004
Messages
5,982
Reaction score
380
Country
United Kingdom
I usually get the lighting rep from Eddies to spec up jobs like this, he will either do it or get the guy from Ansell to do it
 
Joined
27 Jan 2008
Messages
19,653
Reaction score
1,886
Location
Llanfair Caereinion, Nr Welshpool
Country
United Kingdom
I would also say call your supplier and get some expert advice, I got into trouble over lighting, two problems with same premises, one was low bay lighting which worked great when mounted 20 foot up in one building but failure at 8 foot up in another, and second was a 400 watt lamp on a silo which it seemed over 150 watt needs planning permission, which had not been applied for, fact the lamp had been there for years did not seem to matter, no one complained until I renewed the bulb, likely I had altered the angle slightly when I renewed it. After that kept to under 150 watt.
 
Joined
30 Dec 2018
Messages
11,023
Reaction score
1,535
Country
United Kingdom
They have asked me about replacing the existing lights with LED fittings to reduce energy usage and maintenance. The customer is happy for all the new lighting to be 4000k cool white, but would like to keep the existing level of illumination. There are residential properties opposite this building.

I think they will be disappointed, if they expect much of an increase in efficiency, LED is not that much more efficient than SON, but life expectancy might be better.
 
Joined
22 Sep 2009
Messages
641
Reaction score
99
Location
Nottinghamshire
Country
United Kingdom
I think they will be disappointed, if they expect much of an increase in efficiency, LED is not that much more efficient than SON, but life expectancy might be better.

I agree -

filament lamp replaced by LED - a huge decrease in power & rise in efficiency perhaps as much as 10 fold

flourscent lamps replaced by LED - still less power but now only around 1/2 the power for the same output.

HID to LED - not much difference at all really. The higher power LED fittings are very expensive still.
 
Sponsored Links
Joined
11 Jan 2010
Messages
7,783
Reaction score
641
Location
London
Country
United Kingdom
flourscent lamps replaced by LED - still less power but now only around 1/2 the power for the same output.
Not my experience at all. Look at the lumen outputs.


4 ft florescent 36watts 3350 lumens. 93 lumens per watt.


4ft LED 22watts, 1900 lumens. 86 lumens per watt.

It would seem LEDs are less efficient.
 
Joined
10 Mar 2007
Messages
10,455
Reaction score
2,166
Location
Poole, Dorset
Country
United Kingdom
what wattage of LED fitting would be required to replicate a 400w SON flood
Unfortunately for them it's in the same range - 400 to 500 watts for the same lumen output.
There may be some savings to be had as LEDs are far more directional, so lower output fittings can be used as more of the light gets to where it's wanted.

The real question is whether that massive amount of lighting is actually required.
An assessment of what illumination levels are appropriate and the best way to provide them is essential.
 
Joined
31 Mar 2006
Messages
20,000
Reaction score
1,381
Location
Leeds
Country
United Kingdom
Not my experience at all. Look at the lumen outputs.


4 ft florescent 36watts 3350 lumens. 93 lumens per watt.


4ft LED 22watts, 1900 lumens. 86 lumens per watt.

It would seem LEDs are less efficient.
You see this is where real world experience proves book learning and quoting specs of a poorly designed product to try and show how clever you are wrong. You also forgot about ballast inefficiency but never mind.

I recently designed a project in a sports hall which was previously lit by 15x twin 6’ fluorescent fittings with a measured power consumption of 2.25kW. They were replaced by 35x 35w LED fittings so a total power consumption of 1.225kW.
The light levels were measured with a lux meter at 20 fixed points across the hall before and after the upgrade and the light levels increased at every point, yet the overall power consumption was reduced by 1000W.

More light for significantly less power. I’d say that proves that LED is more efficient than fluorescent lighting.
 
Joined
11 Jan 2010
Messages
7,783
Reaction score
641
Location
London
Country
United Kingdom
I can’t explain your different experience. Adding 5 w ballast loss in my example reduces the lumens per watt of the fluorescent to 82. Not enough to warrant the expense of changing IMO.
 
Joined
18 Jul 2004
Messages
8,517
Reaction score
406
Location
Devon
Country
United Kingdom
I've had good results with 200 watt Ansell Mira flood lights replacing 400watt SONs. I'd say a little brighter, and the throw of light is very good.
 
Joined
28 Jan 2011
Messages
50,464
Reaction score
3,401
Location
Buckinghamshire
Country
United Kingdom
... a car park lit with 400w SON floodlights .... There are residential properties opposite this building. .... if anyone has a recommendation of a make which .... has a good output pattern so as to not cause too much light pollution on to the nearby properties.
Is there a bit of a semantic issue here? Is it not the case that "floodlights" (as opposed to "spotlights") are expected to have a very wide beam angle?

Kind Regards, John
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Top