This credit requires not only the mercury content of the bulbs, but specific life and light output using specified testing methods:
· Life of bulb: 3 hours on/20 minutes off for fluorescent bulbs; 11 hours on for HID lamps.
· Light output of bulb: fluorescent bulbs measured with an instant-start ballast having a ballast factor of 1.0
(exception: T-5 bulbs are measured using program-start ballasts), as measured at 40% of bulb life
The reviewers do not accept life and light output values on manufacturer's cut sheets without the testing methods justified.
The problem is that even the largest leading global manufacturers do not provide or do not have such information available on all of their products, e.g., Philips.
Chances are, projects do not have trouble meeting the criteria, but struggle to document per the credit requirement. A lot of buildings use products with very low mercury level and reasonable rated life and lumen values. However, without manufacturer's information using the specific testing methods, they simply cannot document the credit.
While LEED calls it "industry standard criteria," which is questionable, is there any industry-wise accepted factors that can be applied to "Life to 50% failures EM" or "Rated Luminous Flux EM" to get the values specified?
Any guidance would be very much appreciated.
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
734 thumbs up
May 1, 2014 - 8:52 am
The 3 hours on / 20 minutes off is a standard testing practice in the industry to determine lamp life. If no details are provided then it should be assumed that this was the test used. The "off" period is less important.
Some manufacturers have enjoyed inflating their life expectancy numbers by reducing the number of times a lamp has to start. They'll show a 12 hour "on" cycle. But anytime I've seen this they'll also show the 3 hour cycle to comply with industry standards.
I would try to tell the reviewer that the 3 hour life expectancy test is the industry standard and any published claims for a lamp's life expectancy comply with this standard unless noted otherwise.
The 50% value is how lamp life is calculated. A lab will run 1000 lamps and when the 500th lamp fails you have your average (median) life expectancy. I'm not familiar with "Life to 50% failures EM" or "Rated Luminous Flux EM". I tried googling the terms and only got something from a Philips lamp. I'm not sure what "EM" stands for here. Maybe 'estimated median'? The way it is written on the Philips data sheets I would read it as.
Life of lamp = "Life to 50% failures EM"
Light output of lamp = "Rated Luminous Flux EM".
Simon Sue
SL+A INTERNATIONAL ASIA INC.411 thumbs up
May 4, 2014 - 10:57 pm
Thanks very much for your insight, Bill.
Life of lamp and light output of lamp are clear on the cutsheets, just not the testing methods.
The reviewers have basically stopped accepting values without specified testing methods.
For example, some products would have the following all listed out, and would be easier to justify:
- Life to 50% failures EM
- Life to 50% fail Preheat EL,3h
- Life to 50% fail Nonpreh EL,3h
while others only have one life of lamp listed:
- Life to 50% failures EM
so it is hard to tell if it actually followed the 3 hours on / 20 minutes off standard.
Light output is of the same issue. There is always a rated lumen value on the cut sheet, but you'd never find the wording "measured with an instant-start ballast having a ballast factor of 1.0, as measured at 40% of bulb life" from a manufacturer.
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
734 thumbs up
May 5, 2014 - 8:50 am
Preheat = a programmed start ballast.
Nonpreheat = an instant start ballast.
Lumens are listed in one of two ways. Either an initial value or a maintained (mean) value.
Here's a sample cut sheet. Information overload. But this should have everything a reviewer wants to see. http://download.p4c.philips.com/l4b/9/927869785102_na/927869785102_na_ps...
Mercury Content = 1.7 mg
Design Mean Lumens = 2,935 Lm
Rated Avg Live [3-Hr Inst St] = 24,000 hr
1.7mg = 1,700,000,000 pg
1,700,000,000 pg / (2,935 Lm * 24,000 hr) = 24 pg/LmHr
GE's website many years ago only had a picogram value for the mercury content. I had to bug them to list the total lamp content. Even big companies can be responsive if you ask a question. But it may take 2 or 3 responses back and forth before they understand what you want.
Do you have a link to the cutsheet that you submitted and what the exact words were that the reviewer said? Someone seems to be overthinking what is needed.
Simon Sue
SL+A INTERNATIONAL ASIA INC.411 thumbs up
May 9, 2014 - 12:01 am
Hi Bill,
Thanks for your input again.
If only every cut sheet looks like the one you showed.
Most cut sheets we run into look like this:
http://download.p4c.philips.com/l4b/9/927983286536_eu/927983286536_eu_ps...
They would have 10% failure life, 50% failure life, and rated lumen. And that's it. No 3-hr and no mean lumen, or lacking one or the other. And the manufacturers don't usually respond to the requests of additional information or additional testing results. In such cases, reviewers would comment like below:
1. Please provide manufacturer documentation that verifies the rated life values listed on the form based on 3-hour instant start values,
as outlined above.
2. Provide manufacturer documentation that verifies the light outputs listed on the form based on mean lumen values, as outlined
above.
I know it's simply two line items on the manufacturer's cut sheet, but they're not usually available.