[esp-r] Re: Start-up days and quasi steady-state

[Georgios Kokogiannakis]

Dear Liam,

there is some data for the start-up days available in the trace facility. You have to use the "Invoke trace facilities" option (run an interactive simulation to find it).
Not sure though about the temperature in your model. It probably depends on the type of building you are trying to study, the boundary conditions, etc.

Regards,
Georgios



-----Original Message-----
From: esp-r-bounces at lists.strath.ac.uk on behalf of Liam O'Brien
Sent: Fri 25/01/2008 22:57
To: esp-r at lists.strath.ac.uk
Subject: [esp-r]  Start-up days and quasi steady-state
 



One more question:

I am interested in observing the effects of a particular climate pattern for a single day that is repeated many times (i.e. quasi steady-state is reached).  I am simulating 36 start up days (to be safe) for a simulation period that lasts only one day.  I acknowledge that the ambient temperature should not necessarily be continuous (i.e. temperature at beginning of the day will not match the end).  However, I am puzzled by the fact that a large thermal mass in my building does not appear to show any effects at 12:30am of the stored heat from the day before.  Basically, the temperature graph of the thermal mass drops from 22C to 19C in an instant.  This indicates that a huge amount of energy disappears.  I have copied the temperature of the node at the center of the mass:

00h30      19.45                                                                                                            
01h30      19.34                                                                                                            
02h30      19.24                                                                                                            
03h30      19.13                                                                                                            
04h30      19.03                                                                                                            
05h30      18.93                                                                                                            
06h30      18.83                                                                                                            
07h30      18.73                                                                                                            
08h30      18.66                                                                                                            
09h30      18.63                                                                                                            
10h30      18.71                                                                                                            
11h30      18.92                                                                                                            
12h30      19.28                                                                                                            
13h30      19.77                                                                                                            
14h30      20.36                                                                                                            
15h30      20.99                                                                                                            
16h30      21.61                                                                                                            
17h30      22.15                                                                                                            
18h30      22.56                                                                                                            
19h30      22.82                                                                                                            
20h30      22.93                                                                                                            
21h30      22.92                                                                                                            
22h30      22.82                                                                                                            
23h30      22.66    

Since the performance data cannot be viewed for the start up days, it's difficult to see what's really happening.  Can anyone suggest what might be happening here?

I am using the native Windows version.

Any insights would be very helpful.  Thanks.

Liam O'Brien







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