[Equest-users] Defining Building and Fixed Shades using Coordinates Alone

[Nick Caton]

Our understandings differ a bit - I can affirm that I and others have tested and shades defined as I'm describing/showing do their job and shade other surfaces that are components of other spaces/shells.

Here's my understanding bulleted out for clarity...  I might be off here so feel free to correct me:

-          Building shades:  Shade everything

-          External surfaces (roofs, walls) generally:  Shade everything as well, unless you set the "self shading" input to "no"

-          Shades defined as a child components of a window (fins/overhangs):  Shade only that window, not the surrounding wall surfaces or adjacent windows



[cid:489575314 at 22072009-0ABB]

NICK CATON, P.E.
SENIOR ENGINEER

Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036
fax 913.345.0617
www.smithboucher.com

From: Arpan Bakshi [mailto:arpanbakshi at gmail.com]
Sent: Tuesday, April 17, 2012 4:06 PM
To: Nick Caton
Cc: equest-users
Subject: Re: [Equest-users] Defining Building and Fixed Shades using Coordinates Alone

Nick, these examples are quite impressive and DO look like a lot of work! A question about the dummy zone approach--my understanding is that any geometry which is a subset of a zone or window only shades the parent object, whereas a building & fixed shade element shades all geometry in the model. How did you bypass this issue? Thank you!



Arpan Bakshi, LEED AP BD+C


On Tue, Apr 17, 2012 at 4:56 PM, Nick Caton <ncaton at smithboucher.com<mailto:ncaton at smithboucher.com>> wrote:
Hi Arpan,

I'd hate to lead you into an unnecessarily time-consuming path, but I have on rare occasion found it helpful to approach defining complex building shades as exterior wall sections under a dummy space, which themselves can be defined referencing a polygon, which in turn can be defined in (relative) XYZ point coordinates...  What you functionally lose along the way is the ability to assign a shading schedule or otherwise alter the opacity of the resulting "shade."

Disclaimer:  Defining shades with exterior wall sections is likely going to be time consuming, however you slice it.  Like anything worth doing, right =)?

If you're interested in pursuing this, you should first consider whether the shade you're emulating  can be represented/approximated in 2D.  I did a writeup once (full discussion attached) showing how one can apply the concept above to represent a complex, repeating shape to pick up the shading of a superstructure.  Here's an illustration showing the end-result:

[cid:image005.png at 01CB5978.13595400]

To up the ante, with another tier of effort you can approach approximating 3D shapes with polygonal exterior wall sections... but I would sooner advise strongly considering whether a 2D equivalent can be defined, or if you might better invest your time learning a more complex-geometry-compliant energy modeling software (I keep meaning to do this!).  Following is a visual of using polygonal exterior wall sections as shades to achieve a 3D shape - this was not a small amount of work:

[cid:image004.png at 01CD1CC2.1BBE9380]

A couple folks have, in years past, developed impressive looking export tools (from the likes of sketchup, revit and so forth) that at least appear to automate production of polygons for complex geometries in eQuest... I've never seen any of these freely distributed nor test-driven any such tool/process myself, so I can't endorse further other than to note they're out there and might be available, for a cost.

Best of luck!

~Nick

[cid:489575314 at 22072009-0ABB]

NICK CATON, P.E.
SENIOR ENGINEER

Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036<tel:913.344.0036>
fax 913.345.0617<tel:913.345.0617>
www.smithboucher.com<http://www.smithboucher.com>

From: equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org> [mailto:equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org>] On Behalf Of Arpan Bakshi
Sent: Monday, April 16, 2012 8:07 PM
To: equest-users
Subject: [Equest-users] Defining Building and Fixed Shades using Coordinates Alone

Fixed and Building Shades are presently defined in DOE2/eQUEST using:

X-REF
Y-REF
Z-REF
HEIGHT
WIDTH
AZIMUTH

Has anyone come across an alternate specification method using coordinates only?
For example:

Point 1 (x,y,z)
Point 2 (x,y,z)
Point 3 (x,y,z)
Point 4 (x,y,z)




Arpan Bakshi, LEED AP BD+C


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