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Re: [EnergyPlus_Support] Strange impacts of changing Set point Tempratures



Yes, it is strange.  My guess is that the system is not controlled properly.  
You must be very specific when you say "cooling loads".  Do you mean the loads 
at the chiller, at the cooling coil, or the cooling delivered to the zone 
(Zone/Sys Sensible Cooling Energy)?  

It is impossible to say for sure what the problem is without seeing your input 
file.  But, here is an example of a system that would behave this way:  A 
constant volume reheat system with a fixed supply air temperature setpoint.  
When the zone temperature setpoint is raised, the mixed air temperature will be 
higher, and the cooling coil will need to provide more cooling to meet the same 
supply air temperature setpoint.  And the reheat load will also increase.  

Mike


On 9 Jan 2008 at 23:55, abeermme wrote:

> Hi,
> I'm investigating the impacts of setting higher set point temperatures 
> for cooling in an office space, for my surprise; the cooling loads 
> increase when I increase the set point temperature from 23c to 24c or 
> 25 then  with 26 and 27c the relation is proportional (as expected), 
> Isn't this strange as it's expected that when the set point 
> temperature is higher, less cooling would be required (as it will be 
> only required when temperature exceeds this set point temperature 
> whose increase should consequently result in less cooling requirement)
> So why isn't this occuring with the increased cooling set point 
> temperature by only +1 or +2C???
> Any possible reasons? or something wrong I've done??
> Please help!..Your replys and comments are very appreciated
> Thank you
> Abeer
> 
> 
> 
> The primary EnergyPlus web site is found at:
> http://www.energyplus.gov
> 
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> 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





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