Re: [EnergyPlus_Support] Report Variables - Gain/Load?

["Michael J. Witte" <mjwitte@xxxxxxxx>]

Please read my reply to "report variable: surface conduction" for a general 
discussion of gain/load components.  With that background, I will mark each of 
the report variables you asked about as GAIN or LOAD

GAIN   a) Report variable, *, Window Transmitted Solar [W]
GAIN   b) Report variable, *, Window Heat Loss [W]
GAIN   c) Report variable, *, Opaque Surface Inside Face Conduction [W]*
LOAD   d) Report variable, *, Zone/Sys Sensible Heating Rate [W]
LOAD   e) Report variable, *, Zone/Sys Sensible Cooling Rate [W]

But note that a, b, and c overlap with each other.  Window Heat Loss (Gain) 
includes many components including solar transmitted in and out through the 
window.  Opaque Surface Inside Face Conduction includes the impact of absorbed 
solar (current and past) as well as a variety of other heat balance components 
on the inside face of a surface including conducted heat from the center of the 
surface construction.

And note that Zone/Sys Sensible Heating (cooling) Rate is the "load" delivered 
by the HVAC system, not necessarily exactly what the zone might require.  For 
example, when a VAV system closes to minimum and the zone thermostat is no 
longer calling for cooling, Zone/Sys Sensible Cooling Rate continues to report 
that cooling has been provided by the min flow of cold supply air into the 
zone.

At the risk of exposing some of my own ignorance and creating a flurry of 
responses, I will ask a question - 

Why/what do you want to know from the simulation regarding loads/gains?  
Questions about loads/gains and component loads come up somewhat frequently, 
and my response is always "its complicated" or "its not easy to sort out".  If 
it were possible to create a new report variable or new report, what would you 
want to know and why?  How would the information be used?

Mike



On 22 May 2007 at 15:49, berlinclownfish wrote:

> Dear EnergyPlus-support,
> 
> I'm wondering whether the following report variables are defined as a 
> GAIN or LOAD?
> 
> a) Report variable, *, Window Transmitted Solar [W]
> b) Report variable, *, Window Heat Loss [W]
> c) Report variable, *, Opaque Surface Inside Face Conduction [W]*
> d) Report variable, *, Zone/Sys Sensible Heating Rate [W]
> e) Report variable, *, Zone/Sys Sensible Cooling Rate [W]
> 
> -----------------------------
> * observed for exterior walls
> 
> I've also consulted the input/output reference section but was unable 
> to answer my question.
> 
> Any feedback is highly appreciated,
> 
> Sandro
> 
> 
> 
> 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
> 
> 
> 
> 
> 


========================================================
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.

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/