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LER: Luminaire Efficacy Rating

Have you ever heard of a factor called the Luminaire Efficacy Rating, or LER?

Luminaire Efficacy Rating is exactly what it sounds like – it is a measure of how efficient a luminaire is, which basically means “how much light does it put out based on how much energy it consumes?”  Imagine it as “miles per gallon” for lighting fixtures; that example is pretty oversimplified, but it’s a good comparison of how the LER relates to the overall efficiency of a luminaire.  LER is expressed in “lumens per watt,” which makes sense if you think about it very briefly – how many lumens does a fixture produce per each watt of power that it uses, or how much light does this thing produce when it eat this much power?

The Luminaire Efficacy Rating generally deals with three important criteria:

  • the efficacy of the luminaire, or how much light it delivers per watt
  • the ability for the luminaire to direct light outside of itself
  • the ability of the luminaire’s ballasts to deliver power to the lamps efficiently

The LER is a factor that the National Electrical Manufacturers Association (NEMA) has put into play – fluorescent luminaires are one of the categories being compared in the case of LER, and the figure compares many factors.  There are three major categories of luminaire types that are broken down with the Luminaire Efficacy Rating – fluorescent luminaires, high-intensity discharge industrial luminaires (arc lamps), and commercial, non-residential downlight luminaires.

I put together an image with the breakdown of the terms and basic definitions – I hope it is helpful!

LER-jimonlight

NEMA breaks down the standards for Luminaire Efficacy Rating in the following documents:

  • Fluorescent Luminaires:
    NEMA LE5
  • High-Intensity Discharge Luminaires:
    NEMA LE5B
  • Commercial (non-residential) Downlights:
    NEMA LE5A

The LER factor mostly deals with luminaires using a ballast.  You can certainly calculate the LER for a luminaire using an incandescent lamp – the difference is that you wouldn’t multiply the Ballast Factor into the equation.  Your new equation would be:

LER = (EFF x TLL)/input watts
Luminaire Efficacy Rating for an incandescent luminaire = the product of the luminaire’s efficiency multiplied by the total lamp lumens of the luminaire, divided by the input watts of the luminaire.  Makes sense, right?  No ballast in an incandescent luminaire!

Let’s look a bit at the definitions in this LER equation.  Not everyone might have heard of all of these figures, and some people might be saying “SAY WHAAAT?”

EFF, or Luminaire Efficiency:
This term refers to the output of the luminaire proportionally to the lamp or lamps’ output.  Technically, it is a measure of the amount of luminous flux of the luminaire divided by the amount of luminous flux of just the lamp itself.

(HEY JIM!  What the heck is luminous flux?)

Luminous flux is the measure of the perceived brightness or “light power” – it’s different than radiant flux, which measures all of the light emitted.  Luminous flux is geared towards what the eye can see and the brain can interpret.

TLL, or Total Lamp Lumens:
This term refers to the total measured (rated) quantity of lumens coming from the lamps.  This amount is also multiplied by how many lamps are in the luminaire.  Pretty understandable, right?  So, for example, if I have a luminaire with 3 lamps with a 2000 lumen output each, the total lamp lumens is 6000 lumens – 2000 lumen lamps multiplied by 3 lamps = 6000 lumens.  Cake.

BF, or Ballast Factor:
Ballast Factor isn’t a difficult thing to understand, but there are a few components to understanding it.  Ballast Factor deals with both parts of the creation of light – the ballast and the lamp.  Ballast factor is the ability of a ballast to produce light from the lamp or lamps that it energizes.  A ballast not only fires up the lamp, but after it’s started, it maintains the processes of the lamp.  The Ballast Factor is measured by taking the lumen output of  lamp and ballast combination and dividing it by a reference lamp/ballast combination.

Reference Ballasts are ballasts that are designed to be nearly “perfect” in order to perform under a particular set of conditions.  NEMA has guidelines set forth for Reference Ballasts, which is how we are able to use them to compare other ballast/lamp combinations.

Luminaire Watts Input:
Another very easy thing to understand – Luminaire Watts Input (also called Watts Input, Input Watts, or a number of terms generally related to the idea) is how many watts of power that the luminaire consumes.

I hope this makes a bit more sense if you didn’t know about it before.  Please send me an email through the contact form if you have any questions!

NEMA Index for Q2 2009 Is Even Lower. That Sucks.

nemalightinsystemsindex1

Well, excellent. </sarcasm>  The NEMA index is at a new low – a 4.3% drop over the terrible numbers from last quarter.  Hey, the awesome banker behavior that’s apparently still going on doesn’t affect absolutely everyone, does it?  From a press release at the National Lighting Bureau:

Silver Spring, MD: The National Lighting Bureau (NLB) reports that second-quarter 2009 NEMA Lighting Systems Index data reveal an additional 4.3% drop from the first-quarter’s then-all-time-low performance. On a year-over-year basis, the Index plunged by almost 25%. And for the third consecutive quarter, no bright spots: Each covered equipment category posted lower inflation-adjusted shipments compared to the second quarter of 2008. Luminaire shipments were hardest hit.

Established in 1998, the NEMA Lighting Systems Index is a composite measure of lamps, luminaires, ballasts, emergency lighting, exit signs, and other lighting products shipped nationally and internationally from the United States by the 450 companies that comprise the National Electrical Manufacturers Association (NEMA), one of the National Lighting Bureau’s founding sponsors and creator of the enLIGHTen America communications campaign (www.nemasavesenergy.org). NEMA members manufacture a wide range of products used in the generation, transmission, distribution, and control of electricity, as well as innumerable end-use products in addition to those used in lighting. The value of NEMA members’ annual shipments totals $100 billion.

The Index uses 2002 data for its 100-point benchmark; second-quarter 2009 performance receded to the 72-point level, its lowest ever.

NLB Communications Director John P. Bachner commented that “the return of the residential market probably began during the second quarter, if not the first, but whatever optimism that uptick generates has to be tempered by recognition of continuing consumer frugality and a fragile labor market. Unfortunately, that situation could dampen the sales of energy-efficient lamps, like CFLs [compact fluorescents]. Even though they can save a small fortune over their useful lives, more energy-efficient lamps have a higher first cost that many consumers are just unwilling to accept right now.”

Optimism about the return of the residential market also must be tempered by realities of the nonresidential market. According to NEMA Economic Analysis Director Brian Lego, the commercial real estate market is getting worse, not better. He noted that “office vacancy rates are fast-approaching the levels observed during the aftermath of the dot-com bust and 2001 recession as financial and business services companies have laid off scores of workers while the manufacturing sector’s downturn has produced a new record high in industrial vacancy rates…. Replacement demand for lighting as well as retrofitting to energy-efficient systems will be dampened as firms try to find short-term fixes to cut costs and restore profitability. Even as economic activity begins to recover within the next few quarters, the sheer amount of vacant office, industrial and retail space available will weigh on new construction activity, and by extension keep a lid on demand for nonresidential-use lighting equipment as late as 2011.”

Bachner said he remains optimistic that lighting retrofits will energize the market sooner rather than later. He commented, “As much as we’ve talked about energy efficiency over the years, we’ve really only scratched the surface insofar as existing nonresidential
buildings are concerned.” He said that the Bureau is in the process of completing several reviews of existing data that “are eye-opening, to say the least.”

The NEMA Lighting Systems Index can be viewed at www.nlb.org/Index/.

Q4 2008 Lighting Systems Index Reaches Ten-Year Low

Well, there’s certainly gotta be better news on the horizon, right?

nemalsindex

Homebuilding is at its lowest point in record, foreclosures are at a high point, and now incandescent lamp sales are up because they’re cheaper than buying compact fluorescent lamps.  What the hell is going on here?

A news story over at The Light Board calls attention to the low score of the NEMA index, and what is going on:

According to the National Lighting Bureau (NLB), just-released NEMA Lighting Systems Index data reveal fourth-quarter-2008 lighting-equipment shipments to be the lowest in the Index’ history, a dubious distinction previously held by third-quarter 2008 Index performance, when shipments contracted 4.3% from the second quarter. In its latest tumble, the Index contracted 4.8 percent from the third quarter to the fourth, resulting in a year-over-year decline of 11.2 percent.

Established in 1998, the NEMA Lighting Systems Index is a composite measure of lamps, luminaires, ballasts, emergency lighting, exit signs, and other lighting products shipped nationally and internationally from the United States by the 450 companies that comprise the National Electrical Manufacturers Association (NEMA), one of the National Lighting Bureau’s founding sponsors. NEMA members manufacture a wide range of products used in the generation, transmission, distribution, and control of electricity, as well as innumerable end-use products in addition to those used in lighting. The value of NEMA members’ annual shipments totals $100 billion.

*sigh*

Let’s all keep our heads up, folks.  I know this will get better.  I’m doing my part, and I know there’s parts for us all to play to keep our industry alive and well.  We’re inventing technologies that are revolutionizing the world’s lighting, and we’re a planet full of very intelligent people.  I love our lighting industries, and I will continue to bring as much news as I can humanly write.

Do you know what an “IP Code” is?

At LDI this year, I heard a lot of talk about IP ratings and IP code, with such numbers being thrown around as “IP 65″ and “oh, that fixture’s awesome, it’s got an IP 68 rating.”

Do you know what that means?  Do you know how to interpret IP Code?

A fixture’s IP (International Protection) rating has to do with how well it is protected against the elements and people sticking stuff inside of it, to be frank.  IP ratings cover two scenarios – “it classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures,” to quote Wikipedia’s entry on IP ratings.

So – the rating system is based off of two numbers and their meaning – the first against things stuck in the enclosure, and the second against water entering the enclosure.  This is basically a more efficient and detailed method of saying something is “waterproof,” as many things do.  There are many levels of “waterproof,” as we all probably know.

The rating system:  FIRST NUMBER

0
No protection against contact and ingress of objects

1
>50 mm
Any large surface of the body, such as the back of a hand, but no protection against deliberate contact with a body part

2
>12.5 mm
Fingers or similar objects

3
>2.5 mm
Tools, thick wires, etc.

4
>1 mm
Most wires, screws, etc.

5
dust protected
Ingress of dust is not entirely prevented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment; complete protection against contact

6
dust tight
No ingress of dust; complete protection against contact

The rating system:  SECOND NUMBER

0
not protected    –

1
dripping water
Dripping water (vertically falling drops) shall have no harmful effect.

2
dripping water when tilted up to 15°
Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle up to 15° from its normal position.

3
spraying water
Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect.

4
splashing water
Water splashing against the enclosure from any direction shall have no harmful effect.

5
water jets
Water projected by a nozzle against enclosure from any direction shall have no harmful effects.

6
powerful water jets
Water projected in powerful jets against the enclosure from any direction shall have no harmful effects.

7
immersion up to 1 m
Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion).

8
immersion beyond 1 m
The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer.

NOTE: Normally, this will mean that the equipment is hermetically sealed. However, with certain types of equipment, it can mean that water can enter but only in such a manner that produces no harmful effects.

If you have a “X” in your IP rating, it means that device has no rating for that number.  For example, you might see IP2X on some of the indoor electrical items you have in your house, such as wall outlets.  That means it is protected against fingers going into the socket, and not rated for water.

Now you know how to read IP ratings.  How does it feel to be “in the know?”