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
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
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
2015-02-24 17:15 GMT+01:00 David Reddy:
Julien,
For the main set of DOE-2 commands/keywords, the symbol values are
defined in the BDLKEY.OUT file that is included in the Data\DOE-2 folder
of eQUEST installs.
Below is a screen shot of an example. In many cases, the SV for an
enumeration is the same as the index # of the list as presented in the
eQ interface, but there are exceptions.
Hi Gang:
Got what should be a simple questions for the gurus..
I have a building which has two water cooled chillers on the first 4 floors. I also have about 30 floors of water cooled DX units. I have a cooling tower and condenser loop set up for the 1st four floors. I am having trouble setting up the water cooled loop for the 30 floors of DX units.?
Can anyone give me a simple example?
Thanks.
John R. Aulbach, PE
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
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 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
_______________________________________________
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
John,
Even though I'm not a guru I'll give it a shot...
Which type of zone HVAC system are you using for those 30 floors with water
cooled DX?
If you look at the help entry for CONDENSER-TYPE:
WATER-COOLED The condenser is water cooled. You must attach the
condenser to a CIRCULATION-LOOP of TYPE = CW or WLHP via the CW-LOOP
keyword. For PSZ, PVAVS and PVVT, use of this value indicates that a
water-to-air heat pump (WLHP) is to be modeled.
If you use PSZ, PVAVS and PVVT, you go to Cooling > Condenser, set
CONDENSER-TYPE = WATER-COOLED, then it will allow you to specify the CW
loop you want to use (CW-LOOP).
If you use a PMZ or PTAC, even though you can select CONDENSER-TYPE =
WATER-COOLED, the GUI doesn't let you enter the CW-LOOP. I'm not sure why,
or if forcing it in the INP file achieves the right results. I'll let one
of them guru chime in on that :).
?
Best,
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
2015-02-25 7:20 GMT+01:00 John Aulbach:
Ah! I wasn't looking in the right file.
Thanks a lot David!
Best,
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
2015-02-24 18:06 GMT+01:00 David Reddy:
John,
I think Julien pretty much summed it up. A few additional comments:
* The SYSTEM:TYPE = WLHP system is analogous to the TYPE = PTAC, in
that this is a zonal system, i.e. each zone specified under that
system is assumed to have an individual WLHP system, and the
principal characteristics identified at the SYSTEM level (heat
source, fan power, controls, etc) are assumed to apply to all the
systems of the individual zones. PSZ and PVVT are single-zone
systems, and it is assumed one system serves all the zones defined
under that system, but only one zone is the control zone. All other
zones simply get air supplied at the temperature dictated by the
needs of the control zone, though zone heat sources can be specified.
* Whenever modeling water-cooled DX systems, pay close attention to
the DOE-2 performance curves. They change primarily depending on
whether the HEATING-SOURCE = HEAT-PUMP or not. If this is the case
in your project, you may need to make adjustments to your
COOLING/HEATING-EIR values, as described in the Volume 2 HELP topic
shown below. In general, it is always important to ensure inputs
like capacity and efficiency are coordinated with the PLR/Temp/etc
points that the curves are normalized to.