make exterior wall an interior wall

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I'm running a simulation on just a portion of a building. eQuest sees all walls of the polygon as exterior walls. In reality some walls are interior and will not have heat transfer. Is there any way to make eQuest see those walls as interior walls? I've thought of defining those walls with super insulation and a large air space so heat transfer is negligible. Anyone tried that?

Reba Schaber Mechanical Engineer, P.E.
LEED Accredited Professional

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Reba,

If you've gone through the wizard your interior and exterior walls should be in tehir correct places.

Interioir walls should separate two spaces, and will define heat transfer between those two spaces. You normally have to define which space is on the other side.

Exterior walls define heat transfer between the space and the outside.

If you are in detailed mode, you can delete one and create the other as a child component to the space. When you say large air space - is that the air cavity in the wall? I'm not sure what resistance eQUEST attributes to the larger air gaps, but in reality air cavities over a certain size (I think 1 inch is probably the upper threshold) increase their convective heat transfer and the cavity resistance should go down (not up).

If your just looking to make it adiabatic, I think you should be fine with just deleting the wall. You will lose the thermal mass of the wall material though.

I would model it as an interior wall - especially if there is a space on the other side.

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Reba,

Are you talking about doing, for example, a retail space with a store front
and it has 2 walls that abut other buildings making them interior? If that
is the case you have to make 2 other blocks of no significant shape next to
the space that you are analyzing as fill in the blank spaces. These are
really place holders for other portions of the building. You will have to
make the items in these spaces use 0 energy by making all their lighting
HVAC occupancy etc. 0. In other words make a schedule that turns on 0 of the
equipment. The 2 spaces that abut the space you are analyzing should be
drawing no energy otherwise they will show up in the analysis. I did this
tutorial in another program.

Thanks,

PETER HILLERMANN

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As further clarification,

If you delete any wall/ceiling/roof, you (1) remove both a source of
heat storage (thermal mass) while also (2) removing any heat transfer
across that surface. As a caution: Losing the first effect can be a
lot more significant that you might assume, depending on what you're
looking into.

If you instead change any interior surface type to "adiabatic" (in the
same wizard/detailed places you might select "air" or "internal"), you
will remove heat transfer while retaining the thermal mass of the
construction. This may be the best route when trying to study a
perimeter classroom in isolation, for example.

Quirky thing is, you can't change an exterior surface type
(roof/floor/wall) to adiabatic, so as Vikram is saying you have to first
create an interior surface, copying across the geometrical properties
(polygon, vertices, azimuth...), then delete the exterior surface. Make
sure to define and assign an interior surface construction (layers) if
the Wizards haven't already set this up for you.

NICK CATON, E.I.T.

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Peter et all,

See my post following this one (I received my copy through the list at
9:07) - I am sure you'll find creating a few internal walls from scratch
(after the wizards) to be much less time-intensive and simpler than
creating dummy spaces with zero energy consumption but equal
temperatures to avoid heat transfer... If this seems confusing ask for
elaboration.

NICK CATON, E.I.T.

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Alright folks...

This is one of a number of things I really wish someone walked me
through when I was new to this - so pay attention if you're learning =)!

Attached images are a "visual guide" walking you through changing an
external surface into an adiabatic internal surface in detailed mode.
It took me 10 minutes to pull these together, but 99% of that was spent
creating/naming the images. The process is simple.

Also, If anyone can answer this: Is there any plan or consideration to
have images and other attachments like this included in the mailing list
archives for future reference? I think it's a bummer that so many miss
out on really important email attachments (excel tools, example files,
studies, and other time savers). If it were possible, I and others
might be more inclined to generate this sort of "mini-guide" visual
response knowing others could find and reference such information in the
future.

NICK CATON, E.I.T.

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I have considered adding a Wiki to the onebuilding.org web
site to allow material related to specific simulation
programs (such as a Frequently Asked Questions for
eQUEST-users) to be posted. The visual guide that you put
together would probably be a good addition. Would a Wiki be
useful?

Jason

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Absolutely... I think it would help all users.

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I think it could be extremely useful depending on how it's implemented.
Lots of industries use it already.

While it's great to have access to the multitude of eQuest opinions, I think
it also has the tendency to be overwhelming for the average new user. For
example, Joe the Newbie asks, "how do I do such and such," which prompts a
cascade of 5 different answers.

If I'm looking for a reference, I'd be more interested in 1 good answer
rather than 5 possible answers.

To address that, would it be possible to create mini "think tanks" composed
of 3-5 volunteer sim professionals (per question) who are willing to
collaborate and come up with that "1 good answer" to be included in the wiki
FAQ?

I'd volunteer my time for that!

Anthony Hardman, PE

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One small addition to the copy geometry picture, if go to the location
drop down on the new wall and select "V1 of the space polygon" eQuest
will populate all the other lower boxes for you.
Great job Nick, much clearer than my explanation with text.
Bruce Easterbrook P.Eng.

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I have zero experience with editing/maintaining/contributing to
wiki-style content, but this sounds like a great idea. Based on my
personal experiences with the current archives, I'd be happy getting 20+
search results if it means finding the answer I need - more often than
not, people have trouble knowing what to ask, so some broad result
returns would probably be a positive for any archive format.

I think you make a good point about quality/quantity of information
though - some kind of open review/editing function would be a very good
idea... I don't think any one person has all the answers!

The magic of these lists is how one simple question can branch and grow
as more people throw their thoughts in - it isn't long before everyone
learns something they didn't realize they needed to know!

I think a powerful feature would be some kind of "submittal review"
upload process where past and current thread discussions could be
nominated for writing a wiki article entry (after the discussion has run
its course, if current). I have a personal archive of emails from
mid-2009, and could easily find a large number of discussions (with
attachments) whose content with some minor editing would probably make
great short articles in and of themselves.

NICK CATON, E.I.T.

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With eQuest there are many ways to skin a cat reflecting the users past
experience and what problem they were solving when they learned the
technique. The eQuest training session skips past much of the important
geometry input to get to some of the meatier subjects. There are a lot
of subjects not covered in training, and many new ideas are evolving. A
Wiki would be great and solve a few problems with this forum. Many
questions are answered over and over. The forum subject lines are not
always indicative of the information contained in the post. There are a
few different opinions on some of the topics. A Wiki would put the
techniques up where other "experts" could put in their 2 cents as well
and a good reference library could be quickly built with the best
answer. It would be very handy at 3 in the morning when you are banging
your head on a wall after missing something simple but critical and most
of the forum is sleeping. Plus I would imagine there would be some new
tricks to be learned by the old dogs too.
Bruce Easterbrook P.Eng.

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I think this is an excellent idea.. Not only for eQuest but for other simulation software.. Currently there is the IBPSA wiki that is active and could be used.

http://bembook.su-per-b.org/index.php?title=Main_Page

As well as the NY chapter of IBPSA has some information..

http://energymodeling.pbworks.com/

The question is.. Should there is a eQuest-only wiki?

Phylroy Lopez B.Eng LEED A.P.

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A perspective:

A lot of people mistakenly sign up for only [bldg-sim] and/or [equest-users] to the exclusion of the other onebuilding.org lists. In reality, there is a TON of useful information/discussion for any individual that is actively posted to the different "sub-groups" here... The body of people contributing across these lists is not something we should risk inadvertently dividing / pulling apart by making an "eQuest" only wiki. Make no mistake - no archive of useful information will ever be as functional as the community people who created it.

My general suggestion is, if any such forum/wiki were to be conceived, it really, really ought to be inclusive of all the onebuilding.org lists, or else it may risk breaking apart the single most useful body of professionals/practitioners/academics that I have ever known. If any final outcome ultimately disperses this group, I'd rather shoot the notion down to start.

NICK CATON, E.I.T.

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IBPSA-USA is developing a wiki, we'd love to have additional contributors
from the Onebuilding community.

Let me know off-list if you are interested in the wiki or IBPSA-USA.

The intention is to cover all areas of simulation for which people will
contribute, but I think you can add some software specific examples if that
was what you could contribute.

-DSE

Sent from my iPhone

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I think if we added a Wiki on onebuilding.org that it would
be available for all of the mailing lists. I would assume
that questions on specific simulation programs (such as
eQUEST) would be on pages devoted that program. Whether
people step forward and create useful content, that I can't
control.

So, if I install a the Wiki software on onebuilding.org
someone (or some group) needs to do some organization and
perhaps some administration. Any interested in helping with
that?

Jason

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I don't mind helping out. I think it will be a useful site.

I don't have experience with wikis though.

Vikram Sami, LEED AP

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I can help out as well.. I have some wiki experience.

We could use MediaWiki.. Simple to set up and is the same engine as Wikipedia with lots of plug-ins. It needs MySql, PHP, and a mailserver, and obviously a place to back up to. There are other wikis depending on the platform onebuilding is using. I've set this up on windows and unix.

Phylroy Lopez B.Eng LEED A.P.

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Also, It would be good if the maintenance / administration was at least co-ordinated by some body or organization...maybe IBPSA international?

Phylroy Lopez B.Eng LEED A.P.

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I don't meant to sound contrarian... but just so it's considered - why exactly should additional bodies (like IBPSA/ASHRAE/etc) gain administrative control over this body? I won't speculate doomsday scenarios, but I am concerned such additional oversight might ultimately water down what topics we are and aren't permitted to discuss openly and freely ($$$) as we are today.

I personally feel the onebuilding.org lists have been administered and moderated extremely well (fairly and unobtrusively) for the period I have been reading and actively participating. My thanks to Jason Glazer and any other unsung heroes making this happen =).

NICK CATON, E.I.T.

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