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Re: [EnergyPlus_Support] Re: A problem of Sensible Heating/Cooling Rate




What version are you running?  These definitions were added in v1.2.1.

On 10 Nov 2004, at 13:34, Michael J. Witte wrote:

> 
> 0.  Definitions of these variables appear beginning on p. 180 (pdf p. 210) of
> the Input Output Reference.  I will admit the definitions are quite brief. The
> answers to the remaining questions can all be explained by reviewing the zone
> thermostat setpoint, zone temperatures, and system supply air temperatures.
> 
> 1. No.  On this day, the system fan is on for all hours with some amount of
> outside air at all times (smaller at night), the zone heating setpoint is 12.8C
> at night and switches to 21.1C at hour 8, the maint heating coil is controlled
> to supply 16C supply air.  The zone temperature in the early morning is floating
> between 15.7 and 16.2C, and some fraction of lights and equipment are always on
> adding heat to the space.  Whenever the zone is >16C, this variable will report
> cooling; <16C heating.
> 
> 2.  At hour 8, the thermostat setpoint increases to 21.1C, so the heating 
> delivered is large to recover from setback.
> 
> 3.  It is not simultaneous at the HVAC system time step.  The values reported in
> the example are averaged or summed over the zone time step which may contain
> multiple system time steps.  As explained before, you must report these
> variables at the "detailed" reporting frequency to see every HVAC system time
> step.  
> 
> 4.  The zone is floating down to the setback temperature while the system 
> continues to supply minimum flow at 16C.  If the zone is >16C, the system is
> cooling the space by default until the thermostat calls for heat to maintain the
> setback temperature.
> 
> Mike
> 
> 
> On 9 Nov 2004, at 2:47, hbn_pch wrote:
> 
> > 
> > 
> > Dear all:
> >   Thanks for Mike's kind reply.
> >   I have searched the document and find it just lists the name of the 
> > variables.There is no specification in the document.
> >   For convenience,I list the values for the whole day in 14th,Jan.
> > I use Space-1 for instance.From 1am to 7am,the Zone/Sys Cooling Rate 
> > values are:210w,217w,220w,215w,218w,219w,208w.The Zone/Sys Heating 
> > Rate values are 0.At 8am,The Zone/Sys Heating Rate value is 2519w,and 
> > the Zone/Sys Cooling Rate is 0.At 9am,The Zone/Sys Heating Rate value 
> > is 167w and the Zone/Sys Cooling Rate  value is 62 w.For the remainer
> > hour,the Zone/Sys Cooling Rate value 
> > are:517w,558w,574w,525w,550w,591w,573w,546w,542w,457w,381w,318w,270w,2
> > 29w,217w,0w.And The Zone/Sys Heating Rate value is 0.
> >   Then problems come:
> > Problem 1:Why there is only Zone/Sys Cooling Rate during 1am to 7am?  
> > And during 1am to 7am,the Zone/sys Air Temp values increase a little 
> > sometimes,if the Zone/sys Air Temp increase,The Zone/sys Heating Rate 
> > value must be positive?
> > 
> > Problem 2:Why the the Zone/Sys Heating value is so big?
> > 
> > Problem 3:Why the the Zone/Sys Heating and The Zone/Sys Cooling Rate 
> > exist simultaneous and the values is so small?
> > 
> > Problem 4:Why there is only Zone/Sys Cooling Rate during the remainer 
> > hours.And in front hours of the remain,the system is on its occpuied 
> > period,but the Zone/Sys Heating Rate value is 0.Why?
> > 
> >   Thanks for all your kind help!
> >   pch
> > 
> > 
> > 
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte" 
> > <mjwitte@g...> wrote:
> > > The Zone/Sys Heating/Cooling report variables are described in the 
> > Input Output 
> > > Reference, as are most report variables.  Search the docment for 
> > the variable 
> > > name to find a description.
> > > 
> > > In this simulation, the thermostat has a setback schedule, so that 
> > is why the 
> > > zone temperatures are cool in the unoccupied period.  Also, during 
> > winter, the 
> > > system has been scheduled to run the fan around the clock.  The 
> > minimum outside 
> > > air schedules is set to 2% during unoccupied hours, so the system 
> > always brings 
> > > in some fresh air.  During the hours that you refer to that show 
> > values for 
> > > Zone/Sys Sensible Cooling, the system is cooling the space because 
> > the mixed 
> > > air is cooler than the zone air.  Remember that the zone/sys 
> > heating/cooling 
> > > variables indicate what the system delivered to the zone, not what 
> > the coils 
> > > are doing.
> > > 
> > > Mike
> > > 
> > > 
> > > On 5 Nov 2004, at 3:09, hbn_pch wrote:
> > > 
> > > > 
> > > > 
> > > > Dear all:
> > > >   I start a simulation of the example of 5ZoneEngChill.idf 
> > attached 
> > > > to the EnergyPlus.
> > > >   For analysis,I add a boiler parameter of Boiler Gas Consumption 
> > > > Rate in the report parameter.I discover that there is only 
> > Sensible 
> > > > Cooling Rate values from 1am to the 7am.But at 8am there is only 
> > > > Sensible Heating Rate values,and these values are very 
> > big.Whereas,in 
> > > > 9am,Sensible Cooling Rate value and Sensible Heating Rate value 
> > exist 
> > > > simultaneous and the two values are very small.For remainder 
> > > > hours,there is Sensible Cooling Rate only.
> > > >   From 1am to 7am,the Zone/Sys Air Temp values are approximately 
> > > > 17C,and from 8am to 6pm the Zone/Sys Air Temp values are 
> > > > approximately 21C.Then the Zone/Sys Air Temp values decrease by 
> > hour.
> > > >   So I'm puzzled.I can't find the reasonable explain.I even did't 
> > > > know what do Zone/Sys Heating/Cooling Rate and Zone/Sys Air Temp 
> > mean.
> > > > 
> > > >   Thanks for all your kind help!
> > > >   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.
> > > > 
> > > > Yahoo! Groups Links
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > 
> > > 
> > > 
> > > ========================================================
> > > Michael J. Witte, GARD Analytics, Inc.
> > > EnergyPlus Testing and Support      
> > > EnergyPlus-Support@g...
> > 
> > 
> > 
> > 
> > 
> > 
> > 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.
> > 
> > Yahoo! Groups Links
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> 
> 
> 
> ========================================================
> Michael J. Witte, GARD Analytics, Inc.
> EnergyPlus Testing and Support      
> EnergyPlus-Support@xxxxxxxx
> 
> 
> 
> 
> 
> 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.
> 
> Yahoo! Groups Links
> 
> 
> 
> 
> 
> 
> 
> 
> 






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