[Bldg-sim] Really need some deep DOE-2 theology on this one..

[Joe Huang]

Maybe I'm missing something here, but why not just change those roofs that you want 
adiabatic to be Interior-walls and then change the INT-WALL-TYPE to be ADIABATIC ?   
Wouldn't that take care of both the heat flow problem as well as the area numbers ?

Joe

Joe Huang
White Box Technologies, Inc.
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On 3/10/2013 9:43 AM, Nick Caton wrote:
>
> I'm with Karen -- I don't think you can simply explain this one away to a LEED reviewer 
> and will need to address/correct the issues you've identified
>
> If I'm not mistaken, "adiabatic" isn't an option for exterior surfaces however, at least 
> through the eQuest detailed mode interface.  You could make a distinct roof construction 
> which has an impossibly low U-value to severely limit heat transfer (to/from exterior 
> conditions), but that won't correct the roof area figures your reviewer is tuned into.
>
> In my opinion, the easiest reasonable thing to do would to assert (if you can) the 
> thermostat setpoints are the identical between floors and therefore it's reasonable to 
> not model heat transfer between floors, which means you can simply delete those 
> "non-exposed" roofs.  Re-defining those surfaces to be adiabatic ceiling/floor (using an 
> interior wall construction) would have the same net effect except to define additional 
> thermal mass for the associated spaces.
>
> The "partially correct" roof surface(s) on the other hand, which are both exposed and 
> sandwiched, ought to be modified equally in both models to correct the exposed portion.  
> How simple/involved this is depends on your project's geometries.
>
> Here's a procedure for a correcting a partially sandwiched, single surface roof.  This 
> is done in detailed mode and assumes wizard-based model assembly:
>
> -Navigate to 3D view, highlight the roof surface to be edited
>
> -Open properties window for that surface via the component tree or right-click context menu.
>
> -Identify the referenced space polygon (green text) in the surface properties
>
> -Scroll down to that polygon in the component tree, right click, create a new polygon, 
> copy the one you identified -- name it anything you'll easily find in a long list.
>
> -Re-highlight that roof surface in the 3D view and open its properties window
>
> -Re-assign the polygon (green text) to the copied polygon with a unique name (will now 
> be red text).  Click Done.  3D view should look like nothing has changed at this point.
>
> oSave a copy of your project separately before proceeding!
>
> -Keeping a clear view of the roof section to be edited, now scroll down and double click 
> on the new copied polygon to pull up its vertices.
>
> -From here, play around with manually removing vertices to identify which consecutive 
> series bounds the sandwiched portion of the surface. You will observe which vertices go 
> away or move in the 3D view behind if you delete/edit these inputs.
>
> -Determine whether you need to define any new vertices, to define the "seam" edge where 
> exposed roof meets exposed wall.  If so, experiment with editing a vertex to determine 
> appropriate X/Y coordinates.
>
> -Once you've identified the vertices to remove and add, for eQuest stability reasons I 
> try to edit existing polygon vertices before removing anything from the list (you'll 
> typically end up with fewer vertices than you started).  This is hard to put to words 
> but bear with me:  From the first vertex, identify the range which should remain (if 
> any), then edit the following vertex points to any new coordinates you may have 
> determined for additional points, then copy the series of vertices to remain from the 
> end of the list up, then finally right-click and restore default to remove all vertices 
> remaining in the list, starting from the bottom.
>
> -For context, I personally do not treat new/edited vertex coordinates super-precisely 
> typically -- anything that looks close to right in the 3D view is good enough for LEED.  
> Remember you'll be doing the same edits to both models.  Don't get worked up over small 
> seams/holes in the picture -- they don't cause roof leaks in in the model!
>
> Procedure for a multi-surface roof (one per space/plenum) is the similar except you do 
> it for each partially sandwiched roof section (don't worry this gets quicker/easier 
> after the first couple).  Those fully-sandwiched sections can either be fully deleted 
> per the above logic, or else re-defined as interior floor/ceiling surfaces if deemed 
> necessary.
>
> Until you wrap up such polygon geometry edits, save separately and often, and run a 
> simulation to test everything is working okay.  I've had some mixed results doing such 
> edits with eQuest interface open.  You may see errors/cautions pop up that can be simply 
> clicked through without consequence.
>
> When all is said and done, one piece of good news is you can save, close, and copy/paste 
> all modified custom polygons between your baseline/proposed models, which makes doing 
> the same edits on the other model as simple as re-assigning polygons (with 3D view up to 
> check your work).
>
> ~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
>
> fax 913.345.0617
>
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>
> *From:*bldg-sim-bounces at lists.onebuilding.org 
> [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Karen Walkerman
> *Sent:* Sunday, September 29, 2013 5:11 PM
> *To:* Patrick J. O'Leary, Jr.
> *Cc:* bldg-sim at lists.onebuilding.org
> *Subject:* Re: [Bldg-sim] Really need some deep DOE-2 theology on this one..
>
> If the "roofs" don't have a zone as the outside boundary condition, then the model views 
> them as roofs exposed to the exterior.  You need to fix this. If the spaces on the other 
> side have the same thermostat setpoints, then the easiest thing to do is set the roof 
> type to "adiabatic". This will save you from having to define new polygons if the floor 
> above has different zone shapes.  For a roof that is only partially covered by the floor 
> above, you need to create the new polygons. Sorry.
>
> --
> Karen
>
> On Sep 28, 2013 9:41 PM, "Patrick J. O'Leary, Jr." <poleary1969 at gmail.com 
> <mailto:poleary1969 at gmail.com>> wrote:
>
> this sounds like you have multiple shells in one model for this to occur?  i'm pretty 
> sure equest views an exterior wall/roof as an exterior wall/roof even if it is bounded 
> by an interior wall.  i had this problem come up on one of my own models where i ended 
> up having a building wing meet the building trunk & as i had put them in as 2 separate 
> shells equest did not recognize the dividing wall where the wing met the trunk as being 
> an interior wall & assigned it (via the wizard) an exterior wall definition.  i didn't 
> catch this until reviewing the unmet load hour ss-r & s-va reports & couldn't figure out 
> why the load was so high.  changed the definition of the wall to interior (with a door) 
> in detailed mode and the unmet load hours went to zero and the load came down.
>
> my understanding (in my case) is that if you create multiple shells and place them with 
> a common wall that you want to be an interior the shell rotations need to be zero, even 
> if you have the separation between the two shells occur at a 45 deg angle (then ask mr. 
> architect about that one).
>
> On 9/28/13 4:47 PM, John Aulbach wrote:
>
> Hi Gang:
>
> I need to elite for this one, and you know who you are..
>
> I am reviewing another party's eQuest model submitted for LEED. The reviewer noted that 
> the roof area far exceeded the actual building footprint.
>
> Well, guess why? Somehow, the other party made several floors ROOFS instead of ceilings. 
> I might be able to simply turn the exterior spaces into interior ceilings, but one roof 
> (over an unheated underground garage) is partially uder the building and partially 
> exposed to the "sidewalk/entrance" of the building.
>
> The BIG Kahuena is this..if a space is crammed next to an adjacent space and one of the 
> spaces claims an Exterioir surface between them, does DOE-2 think that Exterior surface 
> is seeing outdoor conditions? Or does it ignore such a thin and merely considers the 
> heat transfer between the spaces (like the wall/roof is NOT exposed to the outdoors)?
>
> My approach is this (unless you disagree)..leave the Exterior wall/roof along and 
> explain that the model (now in Detailed Edit form) would need major surgery to correct 
> to show actual roof area. Having the "roofs" there versus floors will not change the 
> thermodynamics of heat transfer.
>
> I yield to the floor.
>
> John Aulbach, PE
>
>
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