First time here? Check out the Help page!

Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
4

How to Model Supply Air Temperature Reset?
 
  
 
  
 
 
 
 
 
 
    
        
        asked 8 years ago  
 
 kramerica's avatar  
 
 
 
 
    
        
        updated 8 years ago  
 
 MatthewSteen's avatar  
 
 
 
 
 
Could someone please confirm if I am modeling my supply air temperature reset correctly for a LEED baseline model in OpenStudio 1.11? It should follow ASHRAE 90.1-2007 Section G3.1.3.12 which states, "The air temperature for cooling shall be reset higher by 5°F under the minimum cooling load conditions." My zone cooling setpoint is 75°F and the design cooling supply air temperature is 55°F. I am using  SetpointManager:Warmest with the minimum setpoint temperature at 55°F and the maximum setpoint temperature at 60°F. 
image description 
 
I am following other threads and documentation such as 
 
https://unmethours.com/question/14152... http://bigladdersoftware.com/epx/docs... 
 
Preview: (hide)
 
 
 
 
          
 
Comments
2
Plot the supply air temperature versus air loop flow rate and specific zone air flow rate to see how the HVAC system responds.
rraustad's avatar
                        rraustad
                     (
    
        8 years ago
    )
add a comment
 
 
 
 
 
 1 Answer
    
 
 
                    Sort by »
                     oldest newest most voted 
 
 
 
 
 
  
 
 
 
 
2
 
 
  
 
 
 
 
 
 
 
 
    
        
        answered 8 years ago  
 
 MatthewSteen's avatar  
 
 
 
 
 
Correct, the SetpointManager:Warmest satisfies the PRM requirement. It's also how the OpenStudio Standards create the baseline systems 5-8. 
 
Preview: (hide)
 
 
 
 
         
        link
        
 
Comments
@MatthewSteen What if I have two different setpoint for two thermal zones, connected to a single AHU?
Gio's avatar
                        Gio
                     (
    
        7 years ago
    )
What setpoint manager is necessary for the heating coil in the above example?  Heating room setpoint is 70F.
keb's avatar
                        keb
                     (
    
        3 years ago
    )
1
@Gio that's what the VAVR terminals (or zone equipment) is for.
@keb the SetpointManagerWarmest controls both coils. During heating it's 55F and during cooling it is 55-60F.
MatthewSteen's avatar
                        MatthewSteen
                     (
    
        3 years ago
    )
add a comment
 
 
 
 
  
 
 
 
 

    
        Your Answer
    

 
 Please start posting anonymously - your entry will be published after you log in or create a new account.

    

 
 
Add Answer
 
 
 
 
 
 
 
 
   
  
 
   
 
 
 
 
 
 
 
Training Workshops
   
Careers
   
 
 
 
Question Tools
  
 

        
        
            1 follower
        
    
 
 
 subscribe to rss feed 
 
 
 
 
 
 
Stats
 

        Asked:  8 years ago  
 
 
        Seen: 1,637 times 
 

        Last updated: May 31 '16 
 
 
 
 
 
 
 
 
 
 About | Help |  Privacy | Legal | Contact 
 

        Site design and logo: Copyright © 2015 Big Ladder Software LLC. All rights reserved.

        The Unmet Hours and Big Ladder names and logos are trademarks of Big Ladder Software LLC. 
        

        User contributions licensed under the Creative Commons Attribution Share Alike 3.0 License.
         
 
 
 

        Powered by