[EnergyPlus_Support] Re: A zone setpoint control anomaly with ‘dual setpoint with deadband'

["Elmer Morrissey" <elmofuddly@xxxxxxxxx>]

Hi Fred,

After checking the EIO file, thats what it seems to be, there is no 
cooling load in Zone B during the summer design day.

Thanks for that.

-Elmer

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, fred buhl <wfbuhl@...> 
wrote:
>
> Elmer,
> 
> One thing that happens when you have the 2 setpoints is that the 
program
> may be calculating a cooling load for 1 or more zones in the 
summer. If that
> happens, the system will be looking at 23 degrees, not 20. So it 
will 
> reheat the air
> to 23C (assuming the air coming in is less than 23), rather than 
heating 
> to 20. In
> the soon-to-be-released version we have attempted to eliminate 
this 
> behavior - the
> system will only reheat to the lowest setpoint temperature.
> 
> Fred Buhl
> 
> Elmer Morrissey wrote:
> 
> >Hello all,
> >
> >I would like to know the significance of using `dual setpoint with
> >deadband' with a system that does not have a cooling coil. I was 
using
> >this control for my zone thermostat but I noticed an anomaly. My
> >system contains an economizer, supply fan, heating coil and 
terminal
> >reheat coils. 
> >
> >The heating setpoints are set to 20C. The cooling setpoints are 
set to
> >23C.
> >
> >I was under the impression that since the system is only heating 
the
> >air (and letting hot air through without any additional tempering 
if
> >OA temps are too high), then zone temps would be kept at 20C year 
round.
> >
> >The system itself is supplying air to three zones. If I run the
> >simulation, all system functions seem to work fine except for an
> >anomaly in the zone temps. During the winter: the zones are kept 
at
> >20C. However, during the summer: Zone A and Zone C are kept at 23C
> >while Zone B is kept at 20C. All three zones have been set up the 
same.
> >
> >Can anyone help me in trying to figure out why this is happening? 
> >
> >Kind regards
> >
> >-Elmer
> >
> >
> >
> >
> >
> >
> >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.idf 
and press the "search" button.
> > 
> >Yahoo! Groups Links
> >
> >
> >
> > 
> >
> >
> >
> >  
> >
>






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