Re: [EnergyPlus_Support] A zone setpoint control anomaly with ‘dual setpoin t with deadband'

[fred buhl <wfbuhl@xxxxxxx>]

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
>
>
>
> 
>
>
>
>  
>


The primary EnergyPlus web site is found at:
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The group web site is:
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Attachments are not allowed -- please post any files to the appropriate folder in the Files area of the Support Web Site.

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