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[EnergyPlus_Support] Re: AirTerminal:SingleDuct:ParallelPIU:Reheat not cycling
Thanks for the response!
Are you aware of way to go around this? My problem is that if I leave the PIUs available through out the night they will run continuously to maintain the setback temperature. I think because there is not throttle range (deadband) the control on the PIU matches the setpoint temperature and stays on. This seems to have a significant impact on the fan energy. I guess I can try to use an average between the two extremes (on/off). We are trying to model the ashrae baseline 8.
thanks
moana
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Chandan Sharma <csharma@...> wrote:
>
> Hi,
>
> If you asking to specify night cycle availability manager for parallel
> PIU, it is not possible. Currently, availability managers can not be
> specified separately for exhaust fans and PIUs. Instead, the
> availability status for AirLoopHVAC object is applied to these zone
> equipment. In future, this flexibility might be extended to exhaust fans
> and PIUs.
>
> Hope this helps.
>
> Chandan
>
> On 6/14/2011 4:23 PM, moana wrote:
> >
> > Hi All,
> >
> > Sorry if this is an obvious question but I haven't managed to get the
> > parallel PIU cycle at night. I got it work on the singleduct terminal
> > as in the example but unsuccessful with the parallel PIU.
> > Do they work with night cycle?
> >
> > Thanks
> >
> > Moana
> >
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> > <mailto:EnergyPlus_Support%40yahoogroups.com>, "moana"
> > <moana.reynau@> wrote:
> > >
> > > Richard,
> > >
> > > Do you know if PIU parallel fan with electric reheat can utilize
> > cycling fan mode? I've been able to have the singleDuct:VAV:reheat
> > terminal cycle but not the parallel PIU...
> > >
> > > Thanks
> > >
> > > Moana
> > >
> > >
> > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> > <mailto:EnergyPlus_Support%40yahoogroups.com>, Richard Raustad
> > <RRaustad@> wrote:
> > > >
> > > > There is no deadband on Tstat setpoints in E+. If you want the fan to
> > > > cycle, set the fan operating mode schedule to 0. This only works for
> > > > systems that can utilize cycling fan mode. For example,
> > UnitarySystems,
> > > > Furnaces, and some ZoneHVAC equipment.
> > > >
> > > > AirLoopHVAC:Unitary:Furnace:HeatCool,
> > > > CyclingFanSchedule, !- Supply Air Fan Operating Mode Schedule Name
> > > >
> > > >
> > > > On 6/3/2011 2:06 PM, moana wrote:
> > > > >
> > > > >
> > > > > Sorry All,
> > > > > Disregard my previous message, when i exported the geometry from
> > > > > design builder it assigned a schedule to the reporting of the
> > mean air
> > > > > temperature which shifted the curve when i was viewing it in the
> > > > > Result Viewer.
> > > > > I had another question though. When using the dualsetpoint
> > thermostat
> > > > > is there a way to enter a deadband on the heating and on the
> > cooling
> > > > > setpoints? As deadband I mean for example if the heating
> > setpoint is
> > > > > 20C, i would like to allow a +/- 1 degree around it so that the
> > fans
> > > > > don't run constantly but intermittently rather.
> > > > >
> > > > > Thanks
> > > > >
> > > > > Moana
> > > > >
> > > > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> > <mailto:EnergyPlus_Support%40yahoogroups.com>
> > > > > <mailto:EnergyPlus_Support%40yahoogroups.com>, "moana"
> > > > > <moana.reynau@> wrote:
> > > > > >
> > > > > > Hi All,
> > > > > >
> > > > > > I'm trying to model a simple VAV system with local reheat (PIU).
> > > > > When I set up the availability of the air terminals to - always
> > on -
> > > > > The indoor temperature is maintained within the setpoints. The
> > problem
> > > > > is that at night the parallel fan runs all the time. When I set
> > up a
> > > > > schedule with the fans off at night there is a short swing in
> > > > > temperature in the evening below the setpoint (17 deg C). Then the
> > > > > temperature goes back to normal.
> > > > > > I checked the sizing of the heating coils and flow. Entered the
> > > > > values back manually and tried to oversize as well (doubles the
> > > > > capacity) without any effect.
> > > > > > I also checked the timestep and bumped it to 30. No change.
> > > > > > If you check the attached file the problem occurs in the winter
> > > > > (there's an example around 4th Dec).
> > > > > > There's an old post from 06 refering to a similar problem.
> > > > > http://tech.groups.yahoo.com/group/EnergyPlus_Support/message/6649
> > > > > > Not sure if this is still the same.
> > > > > >
> > > > > >
> > > > > > Thanks for your help!
> > > > > >
> > > > > > The idf file is in the Files/Problem_submittals folder.
> > > > > >
> > > > > >
> > > > > > Moana
> > > > > >
> > > > >
> > > > >
> > > >
> > > > --
> > > > 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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