[Equest-users] Interior Walls show up as Exterior Walls
Nicholas Caton
ncaton at catonenergy.com
Mon Jul 20 11:13:06 PDT 2015
Further to Jeff’s suggestions: if you determine it is not necessary to
simulate interior walls AT ALL between the shells (and this is a totally
valid conclusion for many situations), you could very simply proceed with a
plan to, as soon as you are done with wizard-level edits, delete the
resulting “sandwiched” exterior surfaces from the component tree, first
thing. No walls defined is the exact same effect in the simulation as
defining one or more adiabatic walls, excepting there will also no longer
be any thermal mass to retain heat between the hours as would occur with a
layered adiabatic construction.
On the aside & from a teaching perspective, that’s the first time I’ve come
across the resistor / resistor+capacitor analogy to describe surface type
behavior – I like it!
As to zoning resolution, I like to think of this issue as striking a
balance of being *intelligent* enough to define the minimum # of zones as
you will need, and *wise* enough to combine zones to the extent it won’t
make a difference. In practice, my comfort margin for zoning
simplifications shrinks the earlier simulations are engaged to inform
design. For my earliest schematic/planning phase explorations, I find
myself weighing whether to start with a high-resolution model (which will
have the flexibility to carry forward with any number of necessary system
types and zonal distinctions), or else to plan for a single or series of
quickly generated basic/simplified models which I’ll be comfortable
ditching when it comes time to develop a higher resolution, “whole-picture”
study. Where I land on that call depends and varies by building, by the
team of designers you’re working with, by gaging how much thought/effort
the design team places before design development, and of course by the time
I have available to provide the best set of guidance/answers.
Related food for thought:
- For projects requiring detailed documentation later, it’s also
worth considering a minute saved during simulations in design (by combining
similar zones) may require ten minutes when it comes time to document and
explain how the various inputs correctly add up for a multi-zonal system.
- It may also be helpful to recognize that with experience, your
time-efficiency for defining geometries in eQuest (or any program) will be
honed. At some point, the extra time required to define twice as many
zones as the minimum may not be a big deal in the scheme of things.
~Nick
*NICK CATON, P.E.*
*Owner*
*Caton Energy Consulting*
603 N Ferrel
Olathe, KS 66061
office: 785.410.3317
www.catonenergy.com
*From:* Jeff Haberl [mailto:jhaberl at tamu.edu]
*Sent:* Saturday, July 18, 2015 12:02 PM
*To:* Nicholas Caton; David Griffin II; bfountain at greensim.com; Daniel
Caporizzo; equest-users at lists.onebuilding.org
*Subject:* RE: [Equest-users] Interior Walls show up as Exterior Walls
Dan,
One thing to also consider is whether or not you need the interior walls in
the first place since these are basically resistors (i.e., wall = U-VALUE)
or resistor-capacitors (i.e., wall = LAYERED) between two thermal zones. In
addition, you need to consider if the different thermal zones have
different interior temperature settings, as only in this case the interior
walls begin to play a role in the thermal simulation.
In general, EQUEST and other simulation programs tend to use 5 zones in a
model: i.e., N, E, S, W and core zone. However, a review of the literature
seems to indicate that there have been very few definitive studies that
have answered the question: Why 5 zones versus 2 (i.e., core and
perimeter), or 9 zones versus 5 zones, etc.? or What about opaque walls
versus windows versus slab on grade? or What about thermostat settings?
This last question is critical to understanding how newer systems are
impacting energy efficiency as we move towards thermostats with motion
sensors and individual zone systems (i.e., VRF or mini-splits).
Furthermore, to make things worse, some vendors are moving towards
"robo-zoning", without providing a basis for the "robo". So,
long-story-short, unless you are doing something fancy try one zone, then
two, then five, then nine. Unfortunately, to do this you'll have to dump
out the BDL from your first run with the Wizard, then edit and rerun with
the DOE2.2 engine, since EQUEST has built-in assumptions about zoning that
are adding unnecessary zones to the model (i.e., if the thermostat settings
are the same).
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.............................
http://esl.tamu.edu
8=/ 8=) :=) 8=) ;=) 8=) 8=() 8=) :=) 8=) 8=! 8=) 8=? 8=) 8=0
------------------------------
*From:* Equest-users [equest-users-bounces at lists.onebuilding.org] on behalf
of Nicholas Caton [ncaton at catonenergy.com]
*Sent:* Saturday, July 18, 2015 12:09 AM
*To:* David Griffin II; bfountain at greensim.com; Daniel Caporizzo;
equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] Interior Walls show up as Exterior Walls
The “plan north” trick looks to get the job done after a quick check in
this case. I can think of a few more tips to add to the pot so long as
we’re contributing:
1. You can right click the bold perimeter lines in plan view of
wizard screen 2 for each shell, manually telling eQuest to make individual
walls adiabatic (an interior type you can later assign thermal ties with if
desired)
2. When you have two shells meet with walls of varying perimeter
length, I have found it a good practice to generate “extra” vertices in the
shell with the longer wall, so that the shell with the shorter wall can
lock its vertices directly to the first.
*NICK CATON, P.E.*
*Owner*
*Caton Energy Consulting*
603 N Ferrel
Olathe, KS 66061
office: 785.410.3317
www.catonenergy.com
<https://teesmail.tees.tamus.edu/owa/UrlBlockedError.aspx>
*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On
Behalf Of *David Griffin II
*Sent:* Wednesday, July 15, 2015 4:39 PM
*To:* bfountain at greensim.com; 'Daniel Caporizzo';
equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] Interior Walls show up as Exterior Walls
Dan,
If Brian’s solution does not work, you can try an approach I’ve used in
previous versions of eQUEST.
In the Wizard under the Custom Zoning Pattern, offset the interiors walls
that are showing up as exterior by ~1’-0” from the edge of the footprint.
This should make the walls interior rather than exterior, and since DOE2
uses area of geometry to calculate things, it should not affect the
accuracy of your model.
Let me know how it goes.
Sincerely,
[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>
[image: Twitter] <https://twitter.com/arch_nexus>[image: Facebook]
<https://www.facebook.com/pages/Architectural-Nexus/179588705397563?ref=ts&fref=ts>[image:
Youtube]
<https://www.youtube.com/channel/UCYRPWKF-yp-AUiI8ia2XfKw?feature=mhee>[image:
LinkedIn] <https://www.linkedin.com/company/architectural-nexus>
*From:* bfountain at greensim.com [mailto:bfountain at greensim.com
<bfountain at greensim.com>]
*Sent:* Wednesday, July 15, 2015 11:21 AM
*To:* 'Daniel Caporizzo'; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] Interior Walls show up as Exterior Walls
I recommend leaving “Plan North” on DD wizard screen 2 as North – then
setting the azimuth as required in detailed edit mode. With Plan North as
North, I find eQUEST does a good job of creating appropriate exterior and
interior walls for adjacent shells. However when the building is rotated
in the wizard, what you describe (all exterior walls) has happened to me as
well.
I hope this resolves your issue.
[image: cid:image001.png at 01D0C230.B8D1A470]
Brian
*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org
<equest-users-bounces at lists.onebuilding.org>] *On Behalf Of *Daniel
Caporizzo
*Sent:* July-15-15 1:09 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] Interior Walls show up as Exterior Walls
Hi everyone,
I am working on an energy model for an office building (see attached pd2
and inp files), in eQuest v3.65.
My problem is that when I create the shells and zones, all of the walls
touching adjacent shells/zones show up as exterior walls instead of
interior walls.
This is a particular problem on all of the “1F” shells in the model, which
should have interior walls when the shells connect. I am using the default
zones right now while the architect works on updating the room layout. I
don’t know if it is just a setting I have unchecked but in the past this
has only been an isolated problem (i.e. couple of walls for the whole job)
rather than the entire project. I am still in the Wizard Data Edit mode
phase of the model, and even though I can fix this manually in Detailed
Edit Mode (by creating interior walls in the same location) I’d like to fix
it in the wizard…which will definitely save me time in the long run.
Has anyone had this problem before?
Thanks,
Dan
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