[Equest-users] LED lighting

[Nicholas Caton]

If you are interested in stepping up the accuracy of your daylighting
simulations way up, and already know a thing or two concerning photometric
studies (or are willing to learn), then check out SPOT.



SPOT is an excel-driven GUI to Radiance.  It has grown recently into a
(for-cost) product that, given a multitude of pertinent inputs concerning
actual daylighting sensor + fixture placements, windows, zoning, and the
sort of inputs typical for a photometric analysis, will perform an annual
set of hourly simulations to determine actual daylighting behavior.  Among
many outputs, it generates fractional schedules for use in doe2/energyplus
to match its findings which you can subsequently import/assign.



Be cautioned: a SPOT analysis for every typical space type however is *no
light amount of work*, and is probably inappropriate for many simulation
scenarios when a faster approximation is going to be fine.



I will also add/supplement:  You might be surprised to find that the
various LTG-CTRL-METHOD options for fluorescent/MH/HPS dimming for
daylighting in eQUEST all produce perfectly linear part load curves when
LTG-CTRL-TYPE is ‘Continuous.’  If you want to modify any of these to
behave more like LED/incandescent sources, specify the minimum power and
minimum light output fractions to be zero or something quite close like
0.02 (I recall the last LED dimming driver I looked up had a minimum
output/input around 2%).



I’m not certain (and would like to learn) whether it’s possible to assign a
non-linear (i.e. quadratic) curve for daylight dimming with DOE-2/eQUEST.
That would actually be a step in the right direction for quickly and more
accurately exploring fluorescent vs. LED at a high level.



~Nick







*NICK CATON, P.E.*
*Owner*



*Caton Energy Consulting*
  306 N Ferrel

  Olathe, KS  66061

  office:  785.410.3317

www.catonenergy.com



*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On
Behalf Of *David Griffin II
*Sent:* Friday, November 06, 2015 3:39 PM
*To:* Haberl, Jeff; Fakeha Sehar; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] LED lighting



Jeff is spot on. It is a little more tricky if you have dimmable daylight
controls as eQUEST only models dimming for fluorescent lights with ballasts
whose performance is not as linear as LEDs when dimmed.



I usually just count the energy savings from dimming LED daylight controls
as conservative rather than find a more accurate way of modeling it.



Has anyone employed a more accurate way of modeling this? Are you willing
to share?



Thanks in advance!



[image: ARCH | NEXUS] <http://www.archnexus.com>



DAVID W. GRIFFIN II

BEMP
ENERGY ANALYST

2505 E Parleys Way
Salt Lake City, UT 84109

*Office* 801.924.5028

archnexus.com <http://www.archnexus.com>

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*From:* Haberl, Jeff [mailto:jhaberl at tamu.edu <jhaberl at tamu.edu>]
*Sent:* Thursday, November 05, 2015 2:20 PM
*To:* Fakeha Sehar; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] LED lighting



Hello Fakeha:



Simulations programs like eQuest and DOE-2 don’t actually model the
lighting, but rather model the heat gain from the lighting.



Therefore, all you really need is the electricity use of the intended
lighting to enter into the input file, in one of several ways (i.e., Watts
or Watt/ft2), then perhaps enter what type of light it is to estimate where
the heat from the light is going.



Jeff



8=!  8=)  :=)  8=)  ;=)  8=)  8=(  8=)  8=()  8=)  8=|  8=)  :=')  8=) 8=?
Jeff S. Haberl, Ph.D.,P.E.inactive,FASHRAE,FIBPSA,......jhaberl at tamu.edu
<........jhaberl at tamu.edu>
Professor........................................................................Office
Ph: 979-845-6507
Department of Architecture............................................Lab
Ph:979-845-6065
Energy Systems Laboratory...........................................FAX:
979-862-2457
Texas A&M
University...................................................77843-3581
College Station, Texas, USA, 77843..............................URL:
www.esl.tamu.edu
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*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org
<equest-users-bounces at lists.onebuilding.org>] *On Behalf Of *Fakeha Sehar
*Sent:* Thursday, November 5, 2015 3:00 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] LED lighting



I want to model LED lighting in eQuest. Any idea how?
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