Using global parameters to streamline modeling

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Does anyone use pre-defined global parameters in an input file that they
import, as a way to streamline the modeling process?

I already have ASHRAE schedules and building constructions in an input
file that I import, but I never use global parameters.

I make most of my universal changes by using User-Defined Default
Values. Am I missing a big opportunity to speed up the modeling process?

Thanks,

Bill

Bishop, Bill2's picture
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Bill,

When I look at most of my project files, the Global Parameters list is
pretty standard, however each parameter is usually project specific, i.e.
Number of Residences, Glazing Ht by Orientation, System Efficiencies.

One thing that can really help speed up modeling is to get fancy with the
user-defined defaults, using basic IF/THEN statements you can setup default
schedules, lighting w/sf, equip w/sf, infiltration etc. based on a trigger
of the space.

Using the C-ACTIVITY-DESC command under the Space Parameters you can label a
space based on use, and have your defaults do the rest of the work for you.

-Robby

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I was going to say the one thing I use them for is reference building
lighting power densities ... but Robby has clearly taken it a giant leap
forward from there.

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I second what Robby said. I use C-ACTIVITY-DESC to assign all the space and zone parameters with user-default formulas. If/then statements work well if you only have a few templates, but if you have more than a few, I would recommend switch statements (a lesson I learned by maxing out the characters allowed). I have global parameters, formulas, systems, loops, basically everything in inp snippets that I import. I use global parameters extensively in formulas. They certainly have the ability to save time.

Jeremy

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Jeremy McClanathan, P.E., BEMP, HFDP, LEED(r) AP BD+C

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Robby,
Could you go over the basics of this C-ACTIVITY-DESC? I stumbled upon
this thread, and it intrigued me, but I can't find what you're talking
about. Where is 'space parameters'? Is this within the schematic of DD
Wizard, or in detailed mode? If you could just get me pointed in the
right direction, I'm usually able to struggle through it and learn on my
own.

Thanks,

Dane Heimerman, EIT

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Bill,

I don't import global parameters from an input file, but I use them a lot for parametric runs. It just makes it easier when setting up the parametric run to change the value of a global parameter instead of searching through the various lists trying to find the name of value to be changed. That searching can be like trying to find a needle in a haystack, especially for people who are new to the program. If a model does not use parametric runs (like separate files for baseline and proposed), then I don't think global parameters would be very useful.

________________________________
Keith Swartz, P.E., LEED AP

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Dane,

What I'm discussing is in the Detailed Edit mode. Part of our efforts to
streamline energy modeling has been to stay out of the wizard as much as
possible. We mainly just use the wizard to setup the building shell, define
slab penetrations, and infiltration rates (i.e. things that are hard to do
in detailed edit mode).

Under the Building Shell tab in, select any space within your project.
C-ACTIVITY-DESC is located here:
[image: image.png]

We use a three letter acronym to describe the space type. In the example
above this space is a corridor. You can then create conditional statements
for most of the Space and/or Zone parameters based on this acronym.

For example, a user default expression for equipment W/SF can be written as
such:
if(#L("C-ACTIVITY-DESC")=="COR")
then (0.25) else
no_default
endif

These statements can have varied levels of complexity due to the nature of
referencing the different variables in eQUEST using the #BDL functions. For
instance, in the above example I'm referencing the local BDL keyword
"C-ACTIVITY-DESC" by using the BDL function #L which references a local BDL
keyword.

Hope this helps,

*Robby Oylear, LEED**?** AP BD+C*

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Thanks Robby, Keith, Jeremy and Brian for your feedback.

I like the idea of referencing C-ACTIVITY-DESC in user input
expressions. What is the size limit of nested If-Then statements if you
want to allow for many space activity types? In particular, would it be
possible to create a user expression that returned the ASHRAE 90.1
baseline lighting value (W/ft2) based on space activity type? I would
want to allow at least 20 or so space types. Could you use a Switch
statement? Is there a way to assign integer values to space activity
types, since Switch needs an integer-compatible expression?

Thanks,

Bill

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I've never used switch because most of the projects we work on have less
than 10 or so space types. I have not ran into a problem where my user
expression had too many characters. From what I understand of switch, you
have to use integers which would require you to have a corresponding Space
Type legend (i.e. 1 = Office, 2 = Corridor, etc.). I prefer to be able to
look at a space in eQUEST and from the activity description know exactly
what it's supposed to be based on the name I've assigned it.

-Robby

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Switch statements can be used with text. You don't have to use integers. I posted a step by step example of how to assign lighting schedules with a switch statement including screenshots and the example model at the following link:

http://www.esimforums.com/equest/viewtopic.php?f=70&t=124&view=unread#unread

I use similar formulas to assign loads, schedules, min flows, osa, etc. Also, as Robby mentioned, I also get out of the wizard as soon as possible to streamline the process. I only create the geometry in the wizard. Everything thing else I can do faster in detailed edit mode. Although it took a lot of effort to get to that point.

Jeremy

___________________________________________
Jeremy McClanathan, P.E., BEMP, HFDP, LEED(r) AP BD+C

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Thanks Jeremy! I added an expanded version of your switch expression as
an esimforums post reply.

I'd like to figure out a quick way of restoring defaults by removing the
appropriate lines in the input file. If anyone knows how to do a
Find-and-Replace in NoteTab Light to remove an entire line, please
describe or give me a call. For example, I believe removing all the
lines for LIGHTING-SCHEDUL keywords under the SPACE commands would
restore the default, which would be much faster than doing a manual
right-click-R for each space in Spreadsheet view.

Thanks,

Bill

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Bill,

What you are looking for is called a regular expression. I actually use excel to do it, but that requires vba. I posted an example of how to do it in NoteTab Light at http://www.esimforums.com/equest/viewtopic.php?f=70&t=125 I'm not familiar with other text editors, but I would assume that all of them would be capable of regular expressions.

Jeremy

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Jeremy McClanathan, P.E., BEMP, HFDP, LEED(r) AP BD+C

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Bill,

My favorite text editor is Notepad++, and yes it is capable of regexp
search.

Simply do Ctrl-H (for search and replace), and search for regexp pattern
(using your example):
^LIGHTING-SCHEDUL.*$
and keep the "replace with" box blank.

Don't forget to tick the regular expression box, and then click replace all.

The regular expression simply means:
search for LIGHTING-SCHEDUL at the beginning of the line (the ^ sign),
followed by any character (the dot) and multiple instances of any
character (the star sign) until the end of the line (the dollar sign)
and replace it with blank (which means delete).

Ery

Ery Djunaedy2's picture
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Thanks Ery and Jeremy. Worked like a charm!

I had to add three spaces in the beginning of the regexp pattern:

^ LIGHTING-SCHEDUL.*$

A blank line remains in the file for each case of LIGHTING-SCHEDUL. I
tried to figure out how to remove the entire line using variations of
the carriage return pattern but didn't have any luck. It didn't seem to
affect the program which ran fine.

Bill

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eQuest will delete the blank lines when you run the model, and may delete them by just hitting save. If you open the file now, the blank lines should be gone.

Jeremy

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Jeremy McClanathan, P.E., BEMP, HFDP, LEED(r) AP BD+C

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