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Re: [EnergyPlus_Support] Re: Cooling set-point not fully achieved
Change your report variable frequency to "detailed" and see if the
square-like profile appears. If it does, you were seeing the average
value for report variables with "timestep" or "hourly" reporting frequency.
anarui.oliveira wrote:
>
> OK, then it goes like this (apparently, the catch was in sizing the
> water flows):
> - basically, I increased these "a lot" and looked at the reported
> maximum flows
> - the reported maximum flow, (with a large maximum design flow, which
> indeed solves the set-point problem) was, not 2, but about 4 times
> larger than the auto-size maximum water flow;
> - which strikes me as odd, specially because the outside temperatures
> in the simulation period are between 7 and 10 ºC lower than the given
> design day;
>
> In any case, the problem is located and solved. Thanks for the
> guidance.
>
> An additional, unrelated question: if the pump if PUMP:CONSTANT
> SPEED, shouldn't the water flow graphics be "square-like"?
>
> Regards,
> Ana.
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com>, Richard Raustad
> <RRaustad@...> wrote:
> >
> > Then try again to manually size the coil in the problem zone to
> twice
> > the size reported in the eio file. Also increase the air flow rate
> for
> > that fan coil unit and fan to twice the autosized value. If htis is
> > happening in more than 1 zone, then just pick 1 for now to test
> this out.
> >
> > Then tell me what happens to the maximum zone temperature. Did the
> > maximum zone temperature go down? Also tell me if the water flow
> rate is
> > at a maximum when the zone temperature exceeds the set point. You
> can
> > report "System Node VolFlowRate" for the coil water inlet node and
> fan
> > coil air inlet node to easily match volumetric flow rate with your
> inputs.
> >
> > This just sounds like a sizing issue and should be easily resolved.
> >
> > anarui.oliveira wrote:
> > >
> > > Apparently, yes, but I set it to autosize (and I think I already
> did
> > > a trial with a larger, user-defined, water flow rate)...
> > >
> > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com>
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>, Richard Raustad
> > > <RRaustad@> wrote:
> > > >
> > > > I have not looked at your input file, can you tell me if the
> water
> > > mass
> > > > flow rate through the fan coil is at a maximum when the cooling
> set
> > > > point is not met?
> > > >
> > > > anarui.oliveira wrote:
> > > > >
> > > > > Please forgive me for insisting, but I DO have some urgency on
> > > this
> > > > > one...
> > > > > Again, thanks for any help,
> > > > > Ana.
> > > > >
> > > > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com>
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>
> > > > > <mailto:EnergyPlus_Support%
> 40yahoogroups.com>, "anarui.oliveira"
> > > > > <anarui.oliveira@> wrote:
> > > > > >
> > > > > > Hi again.
> > > > > >
> > > > > > I'm uploading a new file (Zone36598_cFancoil_exp), hoping
> that
> > > > > someone
> > > > > > can help me figure out why the cooling setpoints are not
> being
> > > > > achieved
> > > > > > for all times when the controls are active (namely in Zone
> > > 36598).
> > > > > The
> > > > > > model consists of Fancoil units created with Compact HVAC,
> and
> > > then
> > > > > > edited in the expanded file.
> > > > > > I tried several user-defined and sizing options, but
> couldn't
> > > solve
> > > > > the
> > > > > > temperature peaks above 25ºC.
> > > > > >
> > > > > > Thanks in advance,
> > > > > > Ana Rui.
> > > > > >
> > > > >
> > > > >
> > > >
> > > > --
> > > > Richard A. Raustad
> > > > Senior Research Engineer
> > > > Florida Solar Energy Center
> > > > University of Central Florida
> > > > 1679 Clearlake Road
> > > > Cocoa, FL 32922-5703
> > > > Phone: (321) 638-1454
> > > > Fax: (321) 638-1439 or 1010
> > > > Visit our web site at: http://www.fsec.ucf.edu
> <http://www.fsec.ucf.edu>
> <http://www.fsec.ucf.edu <http://www.fsec.ucf.edu>>
> > > >
> > > > UCF - From Promise to Prominence: Celebrating 40 Years
> > > >
> > >
> > >
> >
> > --
> > Richard A. Raustad
> > Senior Research Engineer
> > Florida Solar Energy Center
> > University of Central Florida
> > 1679 Clearlake Road
> > Cocoa, FL 32922-5703
> > Phone: (321) 638-1454
> > Fax: (321) 638-1439 or 1010
> > Visit our web site at: http://www.fsec.ucf.edu <http://www.fsec.ucf.edu>
> >
> > UCF - From Promise to Prominence: Celebrating 40 Years
> >
>
>
--
Richard A. Raustad
Senior Research Engineer
Florida Solar Energy Center
University of Central Florida
1679 Clearlake Road
Cocoa, FL 32922-5703
Phone: (321) 638-1454
Fax: (321) 638-1439 or 1010
Visit our web site at: http://www.fsec.ucf.edu
UCF - From Promise to Prominence: Celebrating 40 Years
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