[Equest-users] eQuest Supply temperature as function of outside air (55°F in summer, 70°F in winter)

[Julien Marrec]

Bill,

I've read the thread with attention, and it seems like a clever way to
model it, one I would certainly consider in the future.
(Here I don't have individual plenum spaces and I'm not planning on redoing
my geometry). This thread is from November 2013, so almost a year ago, I'm
curious about what people who have been using this method for a while have
to say about it?

I guess my problem is even deeper. I really don't see how I'm supposed to
be modeling a midpoint or hysteresis controller (such as the ones I
attached to my previous email), no matter which type of system I'm using.
Can someone enlighten me please? What dictates whether my DOAS is in
heating or cooling mode?
Do I have to create a weird heating and cooling schedule manually by
looking at my weather file in excel or something?

Also, is there any way to add custom controllers and write your own logic
(IF Sensor THEN Actuator...) similar to the EMS in EnergyPlus? If I could
write this pseudocode for the midpoint one I'd be ok...
If OAdb < 55°F then
   SAT = 70°F
Elseif OAdb > 70°F then
   SAT = 55°F
Else
  SAT = 125-OAdb
End if

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>

2014-09-22 20:22 GMT+02:00 Bishop, Bill <bbishop at pathfinder-ea.com>:

>  Julien,
>
>
>
> I have had luck modeling DOAS by creating separate systems (as they are
> designed) and assigning them to the plenum spaces above the occupied
> spaces. The description of how to do this, and the merits and potential
> drawbacks, can be found in the “NEW (?) eQUEST DOAS workaround using plenum
> spaces” thread in his archive:
> http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/2013-November/thread.html
>
>
>
> Regards,
>
> Bill
>
>
>
> *William Bishop, PE, BEMP, BEAP, CEM, LEED AP **|** Pathfinder Engineers
> & Architects LLP*
>
> *Senior Energy Engineer*
>
>
>
>
>
> 134 South Fitzhugh Street                 Rochester, NY 14608
>
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>
> bbishop at pathfinder-ea.com <wbishop at pathfinder-ea.com>
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> *From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On
> Behalf Of *Julien Marrec
> *Sent:* Monday, September 22, 2014 1:54 PM
> *To:* equest-users at lists.onebuilding.org
> *Subject:* [Equest-users] eQuest Supply temperature as function of
> outside air (55°F in summer, 70°F in winter)
>
>
>
> Hi,
>
> I'm modeling a DOAS system in eQuest, and the HVAC control sequence
> basically calls for delivering 55°F in cooling mode and 70°F in heating
> mode. The heating/cooling mode is dictated by outside air temperature. This
> is basically in order to deliver "temperature-neutral"* outside air to the
> subsystems (VRV indoor units mostly - and a few corridors with simple
> ventilation grilles. This way the corridors some cooling, and the VRV are
> always only going to handle the thermal load of the space, and not the
> outside air load which is completely handled by the DOAS.
>
> (*I'm more used to see OA being delivered at room temperature, say 70°F,
> but I didn't write the control sequence)
>
>
>
> I've been struggling on how to properly do this in eQuest.
>
> Right now I've got a PSZ system with a control zone being a "dummy zone"
> for which I've assigned a cooling schedule at constant 55°F and a heating
> schedule at constant 70°F. But the hourly output indicates that it's
> basically always providing roughly 62.5°F, so the average of my cooling and
> heating setpoints.
>
> I've tried multiple ways, and read through the archives of the list, but I
> didn't find a working answer (maybe I'm not using the right keywords...)
>
> Basically, is there a way to model either of these two scenarios *in
> attachment *(or online here
> <https://unmethours.com/upfiles/unmethours.com/14114068008016042.jpg>and
> here <https://unmethours.com/upfiles/unmethours.com/14114068157894564.jpg>
> )*,* in eQuest for a DOAS system?
>
> (aside from manually creating an annual schedule that would turn heating
> or cooling off?)
>
>
>
> Thanks a lot,
>
> 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
>
>
> PS: Original post on Unmet Hours:
> https://unmethours.com/question/221/equest-supply-temperature-as-function-of-outside-air/
>
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