[Equest-users] Parametric runs and user expressions

Julien Marrec julien.marrec at gmail.com
Tue Feb 24 08:52:23 PST 2015


Hi David,

I know how to change the value of a global keyword in a parametric run.
When I didn't know is whether I could set one value to be linked to a
global parameter (such as setting the process flow of my HW loop to
"{#PA("GPM_DHW")*500*65/
1000000}" when I switch from a separate water heater to an indirect DHW
heater)

But your elegant solution of a user expression with a global "switch"
solves this, and then more, thanks!

Though I could just use your switch solution, I'm curious about the
symbolic value of global parameters, is it just for built-in keyword
(COLDEST, etc)? Or is there any way I could using a global keyword to point
to a given construction?

FInally, if someone could tell me if there's a surefire way to know what
symbolicValue (#SV) will return I'd appreciate it? Is it just the order of
the associated dropdown list, 0-ordered?

Thanks,
Julien


--
Julien Marrec, EBCP, BPI MFBA
Energy&Sustainability Engineer
T: +33 6 95 14 42 13

LinkedIn (en) : www.linkedin.com/in/julienmarrec
LinkedIn (fr) : www.linkedin.com/in/julienmarrec/fr
<http://www.linkedin.com/in/julienmarrec>

2015-02-24 17:15 GMT+01:00 David Reddy <david at 360-analytics.com>:

>  Hi Julien,
>
> I am pretty sure you can't use an expression to set a global parameter;
> they are limited to being numeric or string (symbol) values.
>
> Unless I am mistaken on what you are after, you can change the values of
> global parameters in parametric runs; see below for an example.
>
>
>
> To my knowledge, no, you can't reset or restore defaults using parametric
> runs, but I can't say I've ever investigated this.  You can use expressions
> that are dependent on a global parameters to set a keyword value to unused
> or no_default. For example:
>
> {if(#pa("901 HVAC Flag") ==1)
> then 45
> else unused
> endif}
>
> -David
>
>
>
> On 2/24/2015 6:48 AM, Julien Marrec wrote:
>
>    Hi,
>
>  Is there a way to implement the following::
>
>  - Use a user expression to set a global parameter's value?
>  ex: define a parameter which refers to another one:
> {#PA("GPM_DHW")*500*65/1000000}
>
> - Use a user expression in a parametric run component?
> Ex: I would like to set one keyword to refer to a global parameter
>
>
>  - In parametric runs, reset values to be default values? Or at least
> specify the "unused" keyword?
>
>  Thanks,
>  Julien
>
>  Side note: this is pretty weird, but if you have a UVT with HEAT SOURCE
> being electricity, it stills include some furnace losses, exactly 800 BTU/H
> (on your fuel meter) which is the DOE default.
> I found this because I've got one example where I have a UVT which Heat
> source is a furnace in my baseline, and it's actually electric in my
> proposed model.
> In my baseline, I have defined a user default for the FURNACE-AUX to be 0
> BTU/H (no pilot light consumption). This 0 BTU/H value stays once I change
> heat source to electricity, and gives me a lower gas consumption that I
> would get if I manually restore FURNACE-AUX to be DOE default (which
> displays "n/a")).
>
>
>
>
>     --
> Julien Marrec, EBCP, BPI MFBA
> Energy&Sustainability Engineer
> T: +33 6 95 14 42 13
>
> LinkedIn (en) : www.linkedin.com/in/julienmarrec
> LinkedIn (fr) : www.linkedin.com/in/julienmarrec/fr
>
>
> _______________________________________________
> Equest-users mailing listhttp://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG
>
>
>
> _______________________________________________
> Equest-users mailing list
> http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to
> EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20150224/9ea3b001/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: bajadejj.png
Type: image/png
Size: 73667 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20150224/9ea3b001/attachment.png>


More information about the Equest-users mailing list