Re: [EnergyPlus_Support] Equipment Scheduling?

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

As you suggest, internal gains, plus outside air, must be at expected peak 
levels during the cooling design day(s) in order to adequately size the coils.  
One quick check is to change the day type on your cooling design day(s) to be a 
Monday and see if this helps the situation.  Also check that the supply air 
temperature controls are consistent with the temperatures in the zone and 
system sizing objects.  And remember that fan heat is neglected in the current 
sizing algorithm.  This can be allowed for by setting teh SYSTEM SIZING cooling 
supply temp a few degrees (equal to the supply fan temperature rise) lower than 
the ZONE SIZING cooling supply temp.

Mike


On 29 May 2007 at 16:20, noelcrrl wrote:

> Dear All-
> 
> I am modeling a building whose HVAC system turns off during hours of 
> non-occupancy.  I have noticed, according to the ESO, that on most 
> mornings, the zones need to be cooled before occupancy.  The HVAC 
> system turns on one hour before occupancy and is very good about 
> bringing the space to temperature before occupants arrive, but it has a 
> difficult time maintaining temperature during occupancy.  I don't know 
> what can be causing this.  My guess is that it might be attributed to 
> the fact that I don't have the equipment scheduled during my design day 
> sizing routines, which can affect my cooling coil sizing.  However, I 
> don't know if this is the real answer.  Does anyone have any advice on 
> this matter?
> 
> Noel
> 
> 
> 
> 
> 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/