[Equest-users] How does eQuest know initialFootcandlesforDaylighting Calc?

[Otto Schwieterman]

Here is an alternate method to eQUEST's daylighting strategies:

 

>From my experience (and training from Marlin Addison), I believe that
eQUEST does not model daylighting with much accuracy. I believe that the
best method to handle daylighting is to run models on independent
software (DAYSIM is free) and insert the results into lighting
schedules. My general practice with lighting schedules is to force 100%
of the lights to be on when the room is occupied and during the same
occupied times, create a new schedule that shows the fraction of lights
on from the DAYSIM output. 

 

This method gives the modeler more control and flexibility with the
model and daylighting strategies. Many times we have 3 rows of lights in
a classroom and we typically force the row furthest from the window
always on when occupied so the minimum percentage of lights on during
daylighting is 33% (1/3).   

 

From: John Aulbach [mailto:jra_sac at yahoo.com] 
Sent: Thursday, January 07, 2010 12:02 PM
To: Matutinovic, Luka; Nick Caton; R B
Cc: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] How does eQuest know
initialFootcandlesforDaylighting Calc?

 

Luka:

 

That was my hope, but eQuest isn't that smart. As I was so directed by
an "unimpeachable source", there IS no footcandle level until you set it
in the Daylighting mode. eQuest then assumes that this is the level 100%
of the lights emit. Then when you allow the Daylighting mode to run,
eQuest lowers the % lighting based on how much you can gain from the
skylights, side daylighting, etc.

 

Crude but straight forward.

 

Others can add or correct..

 

John R. Aulbach, PE, CEM

Senior Energy Engineer

________________________________

Partner Energy

1990 E. Grand Avenue, El Segundo, CA 90245
W: 888-826-1216, X254| D: 310-765-7295 | F: 310-817-2745

www.ptrenergy.com <http://www.ptrenergy.com/>  | jaulbach at ptrenergy.com
<mailto:%7C%20jaulbach at ptrenergy.com> 

 

 

________________________________

From: "Matutinovic, Luka" <LMatutinovic at halsall.com>
To: Nick Caton <ncaton at smithboucher.com>; R B <slv3sat at gmail.com>; John
Aulbach <jra_sac at yahoo.com>
Cc: equest-users at lists.onebuilding.org
Sent: Thu, January 7, 2010 6:09:14 AM
Subject: RE: [Equest-users] How does eQuest know initial
FootcandlesforDaylighting Calc?

Nick,

Does this mean that there is some "baseline" fc that is provided by the
electrical lighting?  That is to say, eQuest will determine how many fc
daylight provides and satisfy the rest with some fraction of the
installed LPD?  This implies that there is a relationship between LPD
and fc, is that true and if so what is it or where could I find it?
Thanks,

Luka Matutinovic, B.A.Sc., LEED(r) AP
Green Building Consultant 

T. 416.644.0649
F. 416.487.9766  
Toll Free 1.888.425.7255
www.halsall.com <http://www.halsall.com/>  

HALSALL ASSOCIATES LTD. 
Toronto  Richmond Hill  Ottawa  Sudbury 
Burlington  Calgary  Vancouver  Dubai 

'50 Best Workplaces in Canada' 
2009 Globe and Mail
P Please consider the environment before printing this e-mail


-----Original Message-----
From: Nick Caton [mailto:ncaton at smithboucher.com] 
Sent: Wednesday, December 30, 2009 10:27 AM
To: R B; John Aulbach
Cc: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] How does eQuest know initial
FootcandlesforDaylighting Calc?

The DOE2 help files suggest, if not directly, that the sensor you are
placing is measuring ONLY "illuminance due to daylight," in isolation of
any electrical lighting in the project.  When you define a "target"
illumation level (say 30fc) at a specific point/orientation, that sensor
will plot the daylight measured in the same vector against a curve
(specified when you select dimming control options) to determine a
factor to apply to the zone's Lightig Watts/SF.

To my knowledge, eQuest in no manner whatsoever is attempting to perform
the operations of photometric software (AGI32/Visual/LightPRO/etc).

~Nick

NICK CATON, E.I.T.
PROJECT ENGINEER
25501 west valley parkway
olathe ks 66061
direct 913 344.0036
fax 913 345.0617
Check out our new web-site @ www.smithboucher.com
<http://www.smithboucher.com/>  


-----Original Message-----
From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of R B
Sent: Monday, December 28, 2009 4:44 PM
To: John Aulbach
Cc: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] How does eQuest know initial Footcandles
forDaylighting Calc?

My guess is that the tool assumes the lighting wattage that you have
gives the amount of footcandles specified. If 50% of this is from
daylight, then remaining is from 50% of the installed lighting
(translating into 50% wattage usage).
-Rohini

On 12/28/09, John Aulbach <jra_sac at yahoo.com> wrote:
> LIke the Phantom of the Opera.."A mystery never fully explained.."
>
> I have performed Daylighting savings EEMs in eQuest, where one places
a
> sensor in the space, one deliniates a minimum footcandle requirement,
and
> runs a Parametric run to determine how much lighting energy may be
saved.
>
> What is NOT clear to me is how eQuest determines what the inital
footcandle
> level is. It obviously knows the lighting fixture height (Ceilling or
> syspended) and the geometry of existing windows, etc. But I cannot
find
> where the information lies that says "eQuest assumes so many
lumens/watt of
> certain lighting."
>
> Can anyone "ILLUMINATE" me, please?
>
> Hope all had a great Christmas.
>
> John Aulbach
>
>
>
_______________________________________________
Equest-users mailing list
http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
To unsubscribe from this mailing list send  a blank message to
EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG

 


________________________________________________________________________________________
Fanning/Howey Associates, Inc. intends to send this transmission (including any attachments) only to the
designated individual or entity.   If you received this message in error, please notify the sender by replying
to the electronic mail (if electronic) or by telephone at the number indicated on this document.
Fanning/Howey Associates, Inc. has taken reasonable precautions to ensure no viruses are present in the
electronic mail.  Fanning/Howey Associates, Inc., will not accept responsibility for any loss or damage arising
from the use of this electronic mail or attachments. Use, disclosure, dissemination, distribution, or reproduction
of this message by unintended recipients is not authorized and maybe unlawful.   Any information included in
this transmission that is not related to contracts with our authorization, verbal or written, by Fanning/Howey
Associates, Inc. may not be covered by our professional liability insurance. 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20100108/c0ca532c/attachment-0002.htm>