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The Lamp Guide

e14 Contributor

A few days ago I received a booklet from RS, to whom I still refer as Radiospares.

It's entitled "The Lamp Guide" and it uses lots of words like "important" and "efficiently" and is very strange.

I say it's strange because among the attributes to help lamp selection it makes no mention whatsoever about the most important parameter: brightness.

I'm certainly not an expert when it comes to lamps, but I do know when it's too dark to see.

Three weeks ago when visiting Ikea I decided to buy a new light fitting for our hallway to illuminate the contents of a new bookcase (the purchase of which was the Ikea visit).

Remembering a trip there several years ago I remarked that the lighting department was easy to find. No need to consult the floor plan.. just head for the huge source of illumination. Wrong. We entered soft furnishings then kitchenware then gave up and consulted the floorplan.

We ended up in a poorly lit, gloomy area full of bright point sources of light.

We selected a set of swish looking super-efficient chrome plated halogen lamps complete with transformers which I duly fitted.

Bad choice. I needed a torch to find the book I was looking for in the new bookcase. Super-efficient should have read "low power".

How does one equate light output from a 5 foot fluorescent tube and an LED lamp for example?

The former produces lots of useful light and the latter a very bright point source of light.

Illumination-wise factors like chalk and cheese.

Turning to another choice.. efficiency. How does one work out efficiency?

I can understand a comparison of 1 watt and 85 watt but how many 6 watt LED lamps with a 35 degree beam angle equals one 65 watt fluorescent tube?

  • sometime around Christmas I was browsing the local home improvement store, there was a display. where they compared a conventional 60W incandescent with a led replacement claiming a 60 watt equivalent brightness. my need to investigate the claims led me to swap the ammeters and there was a better than 10% difference between the two meters. at least one meter had to have been way out off calibration. after asking the "pro" in the electrical isle why they are using crap meters on a display, I received an explanation that the difference between the lights was causing the error. needless to say I contacted the store manager, had a short conversation explaining my little experiment and the conversation with the employee, my next trip to that store both the display and the employee where not there.

     

    The huge pressure from these "green" organizations to reduce "carbon foot-print" has created situations where most consumers have no idea what they are getting into, and poorly trained store employees often cause headaches.

     

    In my experience the best place to shop for lighting, has individual switches for every light. and not a need for extra air conditioning just in the lighting section.

  • Here's a link that will help - but only a little bit !

     

    http://sustainabilityworkshop.autodesk.com/buildings/measuring-light-levels

     

    The problem is that it's very hard to get good data on lighting components sold to a technical market and there is almost no data on products in shops.

     

    eg: CPC (Farnell's cheapo sister company) sell lots of lamps - in a current catalogue an LED floodlight claims "70W power gives 5600 lument output" but on the same page they offer a "Low energy Floodlight" with no mention at all of light output. This seems to be typical - LED lamps often quote lumens (although I suspect they just add aup the headline spec figures of the component LEDs) and nothing is quoted for fluorescent or incandescent lamps.

    I wouldn't be sorry to see an obligation on sellers of lamps to provide a standard measure of light output.

     

    MK