SON-E Efficiency vs. LED

[leavenwill]

Have read in a few places about SON-E bulbs being as efficient as new LED fixtures but here's the problem - I have a 30W cheapy amazon LED lighting up part of my car park (I run a small-ish village pub) and it produces, albeit a different colour, a comparable amount of light to one of my 400W son-e lights.

Do the 400W bulbs use that all the time they are running or do they use more when warming up etc?

For me it's a bit of a no brainer if I am running these for 10-12 hours a day during the winter to have 30W or even 50W LED lights installed to replace the 4 SON lamps to light the front of my pub.

Is there any reason I should stick with the SON's?

 

[flameport]

A 400W high pressure sodium lamp should be around 48000 lumens, or 120 lumens per watt. It uses 400W all the time.

Some high quality LEDs can achieve similar lumens per watt.
However there is no way that the light output from a 30W LED could possibly compare to a 400W SON.

Either the SONs are not 400W, or there are other factors such as light distribution, colour etc.

 

[JohnW2]

A 400W high pressure sodium lamp should be around 48000 lumens, or 120 lumens per watt. ... Some high quality LEDs can achieve similar lumens per watt.

Education time again! Don't SONs generate more heat than LEDs? If they did, they would presumably inevitably be less efficient (in terms of 'light per watt'), so I presume the answer must be 'no'?

Kind Regards, John

 

[ban-all-sheds]

http://en.wikipedia.org/wiki/Luminous_efficacy#Examples_2

 

[JohnW2]

http://en.wikipedia.org/wiki/Luminous_efficacy#Examples_2

It's interesting that (at 38%-44%) the highest luminous efficiency in that table relates to "Theoretical limit for a white LED with phosphorescence color mixing". Even low-pressure SON only goes up to 29%.

Kind Regards, John

 

[eveares]

Remember the total power is not just of the HPS bulb and the LED's, but also the ballast what drive them. A HPS bulb current draw will spike briefly (normally less than a second) to ignite and then the draw will increase steadily until it is fully warmed up.

As a 400W HPS lamp is rated at around 48000 lumens, a 30W LED flood light at around 2400 lumens.

The HPS bulb in theory is 20x brighter than the LED flood light, however it may not appear brighter.

Factors such as the lower colour temperature that HPS bulbs create, old HPS bulbs before they start cycling, and reflectors in the fixture may make the light seem equal in brightness to the LED, but in fact it should be a lot brighter than the 30w LED flood light.

 

[leavenwill]

Ok, it seems on further investigation that these bulbs are pretty ancient and the glass/plastic on the fixtures seem a bit frosted too which all sound like they'll reduce light output potential compared to a new bulb.

Looking at the price of replacement bulbs (£20-£40ish each) I think I may bite the bullet and go with a pair of LED floods and if they don't provide the required lights then at least I still have the SON fixtures to put back up if needed.

Other than being slightly dubious about CE markings etc is there anything massively wrong with the cheapy Amazon LED floods?

 

[flameport]

Other than being slightly dubious about CE markings etc is there anything massively wrong with the cheapy Amazon LED floods?

Are these items being sold by Amazon themselves, or other sellers?

 

[leavenwill]

The lights I have previously bought have been from this seller: http://www.amazon.co.uk/Outdoor-Floodlight-Power-Flood-Light/dp/B00ICXNSBA/ref=cm_cr_pr_product_top

The TLC equivalent being £55 +VAT vs £20 from the Amazon seller. (https://www.tlc-direct.co.uk/Main_Index/Lighting_External_Index/Lighting_Floodlight_Index/LED_Floodlights/index.html)

 

[JohnW2]

The lights I have previously bought have been from this seller: http://www.amazon.co.uk/Outdoor-Flo...p/B00ICXNSBA/ref=cm_cr_pr_product_top[/QUOTE]
I would be fairly nervous: ....

Detailed Seller Information
Business Name: Quantu Wu
Business Type: LTD
Business Address:
No. 121 Zhongshi Street Xukou Town, Wuzhong District
Suzhou
Jiangsu
215000
CN

Kind Regards, John

 

[eveares]

Looking at the price of replacement bulbs (£20-£40ish each)

That is very outrageous!

TLC £8.95 + vat: http://www.tlc-direct.co.uk/Products/LASONT400.html

This is likely your nearest tlc: https://www.tlc-direct.co.uk/Information/branches/CB.html

Or you can get them to deliver for £4.99 + vat

 

[flameport]

Some of these LED lights are ok. Others are not.

Typical problems include:
Earth not connected inside the case, just left loose or sometimes fixed with hot glue
Claimed wattage being wrong, e.g. 10W LED with a 3W driver, 50W fitting with a 20W LED in it.
Defective or reject LEDs used, resulting in the light output being substantially less than it should be.

If buying such things, the only sure way to find out what you have got is to open each one. You'll probably want to do this anyway as the supplied flex is usually far too short.

 

[ban-all-sheds]

Other than being slightly dubious about CE markings etc is there anything massively wrong with the cheapy Amazon LED floods?

Yes - at best shoddy and short-lived, at worst lethally dangerous.

 

[ban-all-sheds]

The TLC equivalent being £55 +VAT vs £20 from the Amazon seller. (http://www.tlc-direct.co.uk/Main_Index/Lighting_External_Index/Lighting_Floodlight_Index/LED_Floodlights/index.html)

So - either people like Thorn, Philips, DAL etc are creaming huge profits, or the Chinese stuff on Amazon & eBay is very cheap in comparison for good reasons.

Only you can decide how much you are prepared to risk on it being the former.

 

[ban-all-sheds]

I would be fairly nervous: ....

Detailed Seller Information
Business Name: Quantu Wu
Business Type: LTD
Business Address:
No. 121 Zhongshi Street Xukou Town, Wuzhong District
Suzhou
Jiangsu
215000
CN

I wouldn't touch them with a barge pole.