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[DSLF] Digest Number 1206
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There are 7 messages in this issue.
Topics in this digest:
1. Another "beam of light" Tower Proposed in NC
From: Mike Hansen <mhansen@einhornresearch...>
2. MIT Technology Review article - "LEDs vs the Lightbulb"
From: "David Penasa" <dpenasa@unm...>
3. Re: High pressure sodium and `bowls`
From: Steve Davis <w2sgd@juno...>
4. Montauk lights changed
From: Susan Harder <lookout@hamptons...>
5. Pole Spacing for FCO
From: "Julie Schaar" <julie.schaar@sbcglobal...>
6. Re: Pole Spacing for FCO
From: "Barry Johnson" <johnsonb52@comcast...>
7. Re: Pole Spacing for FCO
From: ctstarwchr@aol...
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Message: 1
Date: Wed, 3 Dec 2003 16:49:58 -0500
From: Mike Hansen <mhansen@einhornresearch...>
Subject: Another "beam of light" Tower Proposed in NC
Fayettville, North Carolina is planning to build a tower as a new city
icon that will emit "a beam of light shooting into the sky. The beacon
would be visible from Interstate 95." The beam would only be active
when there are events in the park where it is located. Note the irony
that this is to paid for with money "set aside to clean up
environmental hazards."
Fuller details are available at: http://tinyurl.com/xlqe
Mike Hansen
2561 Massachusetts Ave. #1
Cambridge, MA 02140-1020
(617)661-6520
[Non-text portions of this message have been removed]
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Message: 2
Date: Wed, 3 Dec 2003 15:29:46 -0700
From: "David Penasa" <dpenasa@unm...>
Subject: MIT Technology Review article - "LEDs vs the Lightbulb"
LEDs vs. the Lightbulb
With their longer lifetimes and higher efficiencies, light-emitting diodes
will transform the illumination industry-and save billions in energy costs.
By David Talbot
May 2003
http://www.technologyreview.com/articles/talbot0503.asp?p=1
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Message: 3
Date: Wed, 3 Dec 2003 18:49:02 -0500
From: Steve Davis <w2sgd@juno...>
Subject: Re: High pressure sodium and `bowls`
Steve Pauley wrote:
>I suggest the GE M250R2 100w or 150 w hps,
>and then compare both streets using your EYES.
Isn't that just a bit high? Most HPS is 70W
residential and 100W on collector roads.
NELPAG Newsletters 14 and 19 tell the story of
Lexington, MA using 28W compact fluorescent
in FCO fixtures. They even removed one-third
all existing lighting.
Even better is other towns that just shut most
of the lights off or those that didn't have them
to start with and still don't.
Going back to the engineers and uniformity,
that only applies to what is called "continuous
lighting." It is usually for high volume traffic,
high speed, and/or roads with no shoulders.
Most conditions don't require it. -sd
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Message: 4
Date: Wed, 03 Dec 2003 19:54:32 -0500
From: Susan Harder <lookout@hamptons...>
Subject: Montauk lights changed
Here's a nice project. Another "retrofit" of streetlights. These are
"historic" post top lights, on cast iron poles. The light is needed for
pedestrians, not for the streets. Cars are only going about 20-30 mph
through here. There are about 60 poles, and 80 lights. No one
objected. Everyone very pleased.
http://www.indyeastend.com/detail.asp?cat=news&article=1597
Susan
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Message: 5
Date: Wed, 3 Dec 2003 21:27:27 -0600
From: "Julie Schaar" <julie.schaar@sbcglobal...>
Subject: Pole Spacing for FCO
Texas House Bill 916 signed by Geo.W.Bush in 1999, provides for state-funded
roadway lights to be only IES Cutoff status. (See http://www.TexasIDA.org
and click on legislation and state codes.) The Texas DOT engineers argued
against FCO because they might not be able to meet the uniformity standards
required in a certain situation. So they began by using cutoffs, especially
on new construction. I have heard rumors that they are installing some FCO
now, and I've seen some flat-lens cobra-style luminaires; however, I'm not
sure if they are FCO flat-lens.
Maybe someone could tell us which of the flat-lens Cobras are NOT FCO and
how the lumens from a flat-lens light could spill above 90*.
Julie Schaar, Dallas
>The Texas DOT changed out sag-lens fixtures for newer FCO and SCO using
existing mast-arms when Bush was Governor -- no change in existing pole
spacing -- and they're still doing it.
Patric<
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Message: 6
Date: Thu, 4 Dec 2003 00:50:12 -0500
From: "Barry Johnson" <johnsonb52@comcast...>
Subject: Re: Pole Spacing for FCO
A luminaire could have zero candela intensity at or above 90 deg. above
nadir, but if the candela intensity at or above 80 deg. above nadir at some
point exceeds 100 per 1000 lamp lumens, it would not be FCO. In that case
there would be no direct uplight, but the glare zone (80-90 deg.) candela
limit would be exceeded.
Whether any flat lens cobras fit this scenario, only their photometric
reports could reveal. Flat lenses tend to limit the candela at high angles
because the beam must traverse a long path through the flat lens. The arc
tube is also placed above the lens by the thickness of the lamp body, again
tending to limit the output in the 80-90 deg. glare zone.
Barry Johnson
----- Original Message -----
From: "Julie Schaar" <julie.schaar@sbcglobal...>
To: "DarkSky-list" <DarkSky-list@yahoogroups...>
Sent: Wednesday, December 03, 2003 10:27 PM
Subject: [DSLF] Pole Spacing for FCO
> Texas House Bill 916 signed by Geo.W.Bush in 1999, provides for
state-funded
> roadway lights to be only IES Cutoff status. (See
http://www.TexasIDA.org
> and click on legislation and state codes.) The Texas DOT engineers argued
> against FCO because they might not be able to meet the uniformity
standards
> required in a certain situation. So they began by using cutoffs,
especially
> on new construction. I have heard rumors that they are installing some
FCO
> now, and I've seen some flat-lens cobra-style luminaires; however, I'm not
> sure if they are FCO flat-lens.
>
> Maybe someone could tell us which of the flat-lens Cobras are NOT FCO and
> how the lumens from a flat-lens light could spill above 90*.
>
> Julie Schaar, Dallas
>
> >The Texas DOT changed out sag-lens fixtures for newer FCO and SCO using
> existing mast-arms when Bush was Governor -- no change in existing pole
> spacing -- and they're still doing it.
> Patric<
>
>
> _________________________________________________
> To subscribe to the DarkSky List Forum send email
> to: DarkSky-list-subscribe@yahoogroups... or visit:
>
> http://groups.yahoo.com/group/DarkSky-list/join
>
> Help save your town from obtrusive lighting --
> Invite your Planning and Zoning department and
> local officials to join us! Please visit the IDA
> website at http://www.darksky.org frequently, too!
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
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Message: 7
Date: Thu, 4 Dec 2003 03:12:23 EST
From: ctstarwchr@aol...
Subject: Re: Pole Spacing for FCO
In a message dated 12/4/2003 12:47:24 AM Eastern Standard Time,
johnsonb52@comcast... writes:
> A luminaire could have zero candela intensity at or above 90 deg. above
> nadir, but if the candela intensity at or above 80 deg. above nadir at
> some point exceeds 100 per 1000 lamp lumens, it would not be FCO. In
> that case there would be no direct uplight, but the glare zone (80-90 deg.)
> candela limit would be exceeded.
Excellent reply Barry! Nobody, regardless of their level of experience,
can tell the cutoff classification of any luminaire simply by looking at
it in a catalog or in the field. A flat lens luminaire will be a noncutoff
if it emits more than 200 cd per 1000 lamp lumens through any angle at or
above 80 degrees up from nadir, and/or if it emits more than 50 cd per 1000
lamp lumens through any angle at or above the horizontal. Fully shielded is
the best way to describe flat glass luminaires because they usually do not
emit light above the horizontal, but to meet full cutoff, cutoff, or semi-
cutoff classification the intensity must also be restricted below horizontal.
It is also imperative for everyone to clearly understand a luminaire actually
meeting the classification for full cutoff in the photometric report can be
rapidly turned into a glaring noncutoff that emits tremendous glare, light
trespass, and uplight when it is installed with as much as a 5 degree upward
tilt. Excellent justification for communities to require reinforced concrete
pilasters and foundations for the poles in areas that encounter snow in the
winter because this after-the-fact tilting happens frequently when plowing
contractors carelessly slam into the poles and bend them. The pilasters will
assure the contractors equipment gets damaged instead of the lighting system.
Upward tilting of full cutoff luminaires is a common but unacceptable practice
with most fast food restaurants, petroleum retail outlets, and convenience
stores. The plan submittals often get approved for construction based on
the cutoff class indicated because the lighting plan does not stipulate (or
reviewers did not notice) the tilting angle, and the installers apply this
tilting in the field possibly by verbal instruction or out of their own
sheer ignorance of how shoeboxes are designed to perform.
To assure your community gets what is expected, it is vital when specifying
the acceptable equipment allowed in any lighting code, to clearly stipulate
level installations shall occur in the field and prohibit tilting of any
kind so the luminaires perform to the original design characteristics claimed
in the marketing literature and/or what is required by the spirit of the
lighting code. Nearly all Type C photometric reports (area and roadway
fixtures) are developed with the luminaire set to a 0 degree vertical tilt.
The evaluation angle is clearly stated in the report per the IES LM-63
standard for reporting photometric data.
Regarding Julie's question (which & how), several months ago during the
course of my research I discovered serious anomalies in the GE photometry
within their M250R2, M250A2, and M400 cobrahead luminaire families where
the fixtures were claimed to be FCO in the catalog cut sheets and marketing
literature. The photometry file notes stated cutoff (would be accurate by
CIE cutoff standards), but the candela webs for some of these luminaires
indicated a few were semi-cutoff and one or two were actually noncutoff
even though they had flat lenses with no upward tilting. It was impossible
to determine whether any uplighting beyond 90 degrees was occurring because
the photometry was not a full field evaluation and it terminated at the 90
degree vertical angle. (FRUSTRATING!!!) The important thing is not that a
mistake was discovered, but moreso that they fixed the problem immediately.
After speaking at length with the engineering department in Hendersonville
I was informed a reflection anomaly occurred during some of the cobrahead
evaluations and they rapidly sent me some home cooked photometrics that
showed a vast improvement but did not conform to LM-63 in their formatting.
Other techies must have reported these anomalies also because GE is in the
process of redoing their whole photometric library for outdoor luminaires
as well as renaming the reports to reflect the full photometric evaluation
report number to help reduce confusion.
Additionally, instead of the former practice of using either a calibrated
lab grade 1,000 or 10,000 lumen lamp they are now using the proper lumen
output for each wattage application and also evaluate the luminaires to
higher vertical angles. This change in protocol makes rapidly determining
the cutoff class more difficult without using a calculator or evaluation
program, but the benefit is it reduces chances for errors in the field if
designers do not apply the proper lumen package when using the photometry
in their design software. Some outdoor luminaires are now being evaluated
to 120 degrees above nadir (even for the FCOs), and I hope if any intensity
is indicated within the uplighting zone that full field evaluations up to
180 degrees will occur. By all indications, that will probably happen. It
is unknown when the full set of improved photometrics will be available via
the GE web site. Many are still dated 1992 and older.
Within a few weeks, GE will be introducing a new large format roadway and
area luminaire to compete with the Holophane Mongoose. It will be marketed
as the Tiger. Like the Mongoose, it also has a tilting trunion with an
angle indicator on the side. A flat lens option is available that will meet
the full cutoff classification when the fixture is not tilted upward. When
fitted with the flat lens and tilted up it will become a noncutoff that emits
lots of direct uplight and glare. Maximum upward tilt is 45 degrees above
horizontal and it is variable. A prismatic sag lens is available for the
tilted application to help reduce glare and direct uplight. These luminaires
are applied in tilted fashion when large pole setback distance does not allow
the luminaire to hang over or near the outer lane of travel. That is a good
justification to request guard rails because pole setback can be reduced.
The Tiger applies the new tool-less SnapDrive control system that allows
multiple wattage options to be accommodated without a need to change the
ballast, similar to what is used in their Criterion line introduced two
years ago, but currently the lowest wattage available is 250 (HPS or MH).
The Tiger also has a bi-level dimming option available for the SnapDrive
to help conserve energy by reducing light levels and input wattage after
certain hours. The photometry is not completed yet and it is also not shown
in the web or in printed catalogs. Expect to see it soon.
For a preview of the new Tiger luminaire offered by GE you can visit the
Files > Luminaires > Catalog folder in this Forum.
The file name is: CS-111903-Tiger.pdf
Clear skies and good seeing,
Keep looking up!
Cliff Haas
Author Light Pollution Awareness Website (LiPAW)
http://members.aol.com/ctstarwchr
http://www.crlaction.org
Member: IESNA, CRL, NELPAG, AARP
[Non-text portions of this message have been removed]
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