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[EnergyPlus_Support] About temperature control
I'm sorry to update this issue.I want to gain your kind help.thanks
in advance.
At present,i really can't control some months to meet setpoint.For
example,april is controlled but oct is to hot.I use the sensonal
control.How can i control the all year well?
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "hbn_pch" <hbn_pch@...>
wrote:
>
> Thanks for your reply.I've downloaded the lastest version.
>
> I have some more problems and expectation for your kind help.
>
> 1. At present,i'm studying the outside air economizer control.In
> i/o ,it said:"if the outside air temperature is greater than or
equal
> to the mixed air temperature
> set point, the outside air flow rate is set to the maximum; if the
> outside air temperature is less
> than the mixed air temperature set point, the outside air
controller
> will modulate the outside
> air flow so that the mixed air temperature will match the mixed air
> set point temperature."
>
> I can't understand this sentence.So i simulate the
5ZoneEngChill.idf
> for all year to study the result report.But i find,during system
> operative period,the mixed air node temp is nearly the same with
the
> outside air temp,except at the first hour(at 8:00)mixed air temp is
a
> little greater than outside air temp.During uncontrolled period,the
> temp is different from the outside air temp.The mixed temp setpoint
> is the VAV outlet setpoint subtract the fan temp rise.Now that the
> mixed air temp is just the outside air temp,then how does the
> economizer run?Does the temp comparision have significant meaning?
> Probably,i understand it false.Could you explain the control method
> detailed for me?
>
> 2.For all year simulation,during seasonal period,for example in oct
> 5,the outside air temp is high enough.But it is during heating
> period,although the heating coil did not work,the temp in zone rise
> straightly,sometimes reach 28¡æ.It is not comfortable.Can you give
me
> a method to deal with such case?(Taking no account of other
> thing,such as energy waste.I just want to the zone be controlled
well
> and gain the comfort report)
>
> Thanks in advance.
> pch
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Fred Buhl <wfbuhl@>
> wrote:
> >
> > The current EnergyPlus program should handle over cooling by VAV
> systems
> > correctly (by turning on the reheat coils and reheating to the
> heating
> > setpoint).
> > If you are using the current version of EnergyPlus, please upload
> your file.
> >
> > In 5ZoneEngineChiller, the central heating coil is used all year
> (in the
> > current
> > example file I am looking at). Confusingly, there is a schedule
> called
> > HeatingCoilAvailSched,
> > but it is not used. The central heating coil uses the same
> availability
> > schedule as the
> > reheat coils. The cooling coil appears to be scheduled off in the
> > winter, though it
> > is on for the winter design day.
> >
> > Make sure all your coils are scheduled on when you want them to
be.
> Also
> > check the
> > pump schedules. If the pump serving a coil is off, the coil won't
> > operate even if it
> > is scheduled on.
> >
> > Fred Buhl
> >
> > hbn_pch wrote:
> > > Hi,all
> > > I¡¯ve create a model using Standard VAV system without
> > > outside air, hot water reheat coils,purchased cooling and
> heating.
> > > All equipment is autosized. Zone temp control is dual setpoint
> with
> > > deadband. Zone heating setpoint is 20¡æ,coolint setpoint is
> 26¡æ.VAV
> > > supply air temp setpoint seasonal change is 13 ¡æ in summer and
> 16¡æ
> > > in winter.
> > > 1.I simulate for all year and find that some days in summer
> > > are too cold(21¡æ~22¡æ).I check the VAV damper,it is in minimum
> air
> > > fraction.It seems that the supply air is too cold to control
the
> zone
> > > to temp setpoint.Can VAV reheat coil heat the cold air to
remain
> zone
> > > setpoint temperature?How to adjust this days to zone
temperature?
> I
> > > check the vav reheat coil,it is off.
> > > 2.I run the example 5ZoneEngChill.idf for all year.I found
> > > in some day,such as Apr 3,the main heating coil is on at
> sometime,but
> > > the main heating coil scheduled off .I¡¯m puzzled.Does it has a
> > > priority problem?On the other side,if in winter require
> > > cooling,system can turn on the cooling coil although it is
> scheduled
> > > off?
> > > 3.The design day are controlled well,but for all year,some
> > > days are controlled bad.At present I just want to control the
> zone to
> > > temperature setpoint and gain the corresponding thermal
comfort.
> > > Taking no account of other.Does the VAV templet achieve aim?Can
> you
> > > recommend other HVAC system?
> > >
> > > Thanks in advance.
> > > pch
> > >
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > The primary EnergyPlus web site is found at:
> > > http://www.energyplus.gov
> > >
> > > The group web site is:
> > > http://groups.yahoo.com/group/EnergyPlus_Support/
> > >
> > > Attachments are not allowed -- please post any files to the
> appropriate folder in the Files area of the Support Web Site.
> > >
> > > EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf
> under the Documentation link and press the "search" button.
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> >
>
------------------------------------
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