[Equest-users] window shading devices

[Nick Caton]

Hi Kevin!

 

I'm in partial agreement...  I think we'd both agree the person in the best position to judge the appropriateness for a given approximation is the actual modeler.  I'm only bringing up a single shade approach to help brainstorm the options available, not intended to be an exclusively "correct" position.

 

Regarding "blanket rules" for SD vs. "finished" LEED models, I can perhaps productively share for you and Kristin that I have used (and described in documentation) the technique I just described in a final LEED submission (which received 10/10 pts) with no questions raised on the matter.  On the flip side, I have also encountered projects where the combination of overhangs and other shading elements demanded an exacting approach, and have encouraged/assisted others pursuing such levels of detail - evidenced in the archives.

 

Refining and improving a model to a point of "finished" is a case-by-case exercise that requires allocating limited time to different areas within the model - one project may require lots of attention to the shading/glazing systems where another may require that additional time be spent fine tuning the performance curves and scheduling to capture a hydronic systems' particulars.  90.1 and LEED afford the modeler latitude to make reasonable approximations in order to prioritize where to invest their time/efforts.  

 

I personally wouldn't take any strategies of approximation completely off the table before understanding the project more intimately.  Case in point:  A recent list discussion involved a fellow sharing a model so massive in size that certain approximations (which I would rarely use in a smaller "finished" model) were a practical necessity, not an option!  

 

A more general anecdote from the other side of the issue:  Someone following me closely on the lists may have noticed I have a general aversion to using "unweighted" constructions wherever that doesn't match reality.   I accept this as a personal quirk shaped by my own experience - but I'm careful to recognize what makes me feel comfortable for my own projects isn't sufficient grounds for judging others' decisions.  Other modelers have backgrounds/knowledge that permit them to use an unweighted "approximation"  more comfortably and with confidence in the resulting modeled behavior, and that's great!  

 

Long story short - I'm not disagreeing with your suggested practice at all, but only that we leave the responsibility of judging approximations with the modeler ;).  

 

~Nick

 

 

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: Kevin Kyte [mailto:KKyte at watts-ae.com] 
Sent: Thursday, October 13, 2011 9:50 AM
To: Nick Caton; Kristin Gustafson; equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] window shading devices

 

Nick,

 

While I agree that shading devices can be simplified as anything else in energy modeling, one should be careful to the extent this is applied.  For example, I have had to simplify multiple shading devices to a single shade when doing load calculations in Trace.  I think there were five 8" devices projecting from the façade over a single storey and I combined them to one 0.75m shading projection.  It would be fine for schematic.  A LEED or EO111 submission would most likely have the correct shading config.

 

Kevin

 

From: Nick Caton [mailto:ncaton at smithboucher.com] 
Sent: Thursday, October 13, 2011 10:17 AM
To: Kevin Kyte; Kristin Gustafson; equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] window shading devices

 

Taking Kevin's 2nd suggestion a bit further:

 

For a regular/repeating pattern as you're describing, the shading effects could quickly be approximated with a single building shade of a specified transmittance to reflect the mullions' coverage.  There'd be a corresponding single glazing, with no frame and thermal properties defined to match the system as a whole.

 

~Nick



 

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: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Kevin Kyte
Sent: Thursday, October 13, 2011 8:58 AM
To: Kristin Gustafson; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] window shading devices

 

Kristin,

 

You could create one window and then make the other windows "like" the first window using link-to existing.  The window to reference will need to come before all other windows referencing it...

 

Or, this sounds like it might be curtain wall glazing.  If so, you should be able to model a single window and create external shading devices to match the design.  You will have to adjust coordinates to move the device close to the building façade.

 

Kevin  

 

From: Kristin Gustafson [mailto:kgustafson at eypae.com] 
Sent: Wednesday, October 12, 2011 9:12 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] window shading devices

 

Looking for a shortcut here-  

 

I've got a building with lots of glazing, and for a typical 12'high by 24'long wall, there is a shading grid device with horizontal and vertical mullions at 2'spacing (both horiz and vert). Is there an easier way to model this than doing a series of 2'x2' windows ?

 

Is it possible to attach a shading grid to a building face?

 

Thanks

 

 

Kristin Gustafson EIT, LEED® GA 

Energy Analyst

 

EYP / energy

Architecture & Engineering

EYP Energy / NanoFab East / 257 Fuller Rd - 1st Floor / Albany / NY 12203

T 518 438 3720 / C 518 527 3673 / eypae.com <http://www.eypae.com> 

 

/ 2010 Best Firm to Work For

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20111013/c59ead86/attachment-0002.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 1459 bytes
Desc: image001.jpg
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20111013/c59ead86/attachment-0002.jpeg>