Greenbuilding Archive for May 2001

Lamp                         Lumens/watt
 Mercury Vapor               13 - 48
 Fluorescent                    60 - 110
 Metal Halide                  60 - 100
 High Pressure Sodium      45 - 110

When looking at efficiency and cost-effectiveness, don't stop at lumens/watt
though.  For example, HP sodium has a yellow look, and poor color rendering.
Might be suitable for outdoors (if you don't mind not being able to tell
what color your car is) but less suitable for most indoor uses.  The
luminaire efficiency is important as well (i.e., how much light gets out of
the fixture?). Are these for indoor or outdoor use?  Indoors, will they be
on all the time or not?  There are Hi/Lo switches that can be linked to
occupancy sensors to power down the fixtures 50% when they're not being used
(can't just turn HID fixtures on and off because of the start-up time.
These have typically been used in high-bay situations, but there are now
fluorescent high-bay fixtures which might work as well.  Not quite the same
lumens/watt as HID initially, but fluorescents don't degrade as much over
time.  Also fluorescents have better on/off capability which might be more
suitable for intermittent use areas.  If you're going with HID, try to use
pulse start technology with not only give a faster on time, but also have a
more e-efficient ballast and I've heard reduce lumen degradation over time.

Some discussion of technologies/uses at:
http://www.energydesignresources.com/publications/design_briefs/pdfs/lightin
g.pdf
http://infotech.icfconsulting.com/epa/estar/ci/waP2.nsf/attachments/stage1.p
df/$File/stage1.pdf?OpenElement
http://www.eren.doe.gov/erec/factsheets/eelight.html
http://www.eren.doe.gov/femp/procurement/begin.html
http://www-is.informatik.uni-oldenburg.de/~dibo/teaching/mm/pages/light-fund
amentals.html
http://www.tedmag.com/blueprints/Jan_99.pdf
http://www.pnl.gov/techguide/24.htm


Might also check out:
http://www.bathgroup.com/lighting.htm
http://www.ase.org/programs/lighting.htm

Whoops, I just noticed the subject line...these are for street lighting.  Oh
well, I'll post this message anyway, as it might be useful for some.

Hope some of this helps.  The benefits of HPSodium or Metal Halide over
mercury vapor should be easy enough to calculate.

Cheers,
Mike

----- Original Message -----
From: David Porter <dporter@porterarchitects.com>
To: Green Building List <greenbuilding@crest.org>
Sent: Thursday, May 17, 2001 12:27 PM
Subject: [GBlist] Street lighting efficiency study sought


> Anyone know where I can go (web site, preferable) to search for a
comparison
> study between the efficiencies and cost effectiveness of high pressure
> sodium lamps versus mercury vapor lamps?
>
> David Porter AIA
> Palm Beach Gardens, FL USA
> dporter@porterarchitects.com
> www.porterarchitects.com




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