[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [EnergyPlus_Support] Humidistat Problem With Unitary Heatpump/GSHE System
The paragraph on pg 872 is a general statement for using a humidistat.
The Furnace and Unitary Systems are not considered to be a Heat Pump.
Heat pumps can not be (and are not typically) controlled using a
humidistat in EnergyPlus. You must use a Furnace:HeatCool,
UnitarySystem:HeatCool, or DXSystem:Airloop object to control humidity,
but then you will not be able to use a DX Heating Coil.
energyplus99 wrote:
> Is it true that a UNITARYSYSTEM:HEATPUMP:WATERTOAIR, being a "unitary
> system", only needs a ZONE CONTROL:HUMIDISTAT object added to provide
> humidity control? This is what the e+2.0 InputOutput Guide seems to
> suggest (page 872, second paragraph).
>
> Yet when I do this I get the following warnings along with greatly
> dimished control of cooling and humidity after simply adding the
> humidistat:
>
> Calculated Humidity Ratio invalid (ie -0.5387) and
> Temperature out of range [-100. to 200.] (ie 406353.15)
>
> (Just in case a UNITARYSYSTEM:HEATPUMP:WATERTOAIR system has no means
> for dehumidifying (such as controlling the airspeed over the cooling
> coil via the fan) I added a DESICCANT DEHUMIDIFIER:SOLID object to
> boot).
>
> Without the humidistat the system controls nicely for temperature,
> albeit humidity is high for the summer design day.
>
> The enclosure I am using is a simple 3-meter-cubed stucco/insulated
> cube with a single window. So I know that the heatpump/GSHE system
> is large enough to handle any HVAC needs of this small space.
>
> I've uploaded the IDF for this run (CubeSimpleWindow.idf). Would
> anyone have any ideas as to why I'm getting these warnings and the
> consequent poor performance? Am I making the wrong assumptions as to
> what it takes to dehumidify a water-to-air-heatpump/GSHE system?
>
> Any thoughts would be greatly appreciated.
>
>
--
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
[Non-text portions of this message have been removed]
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
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/EnergyPlus_Support/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/EnergyPlus_Support/join
(Yahoo! ID required)
<*> To change settings via email:
mailto:EnergyPlus_Support-digest@xxxxxxxxxxxxxxx
mailto:EnergyPlus_Support-fullfeatured@xxxxxxxxxxxxxxx
<*> To unsubscribe from this group, send an email to:
EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/