[EnergyPlus_Support] Re: Question about the initial load when turn on the chiller

["JV Dirkes II" <jvd2pe@xxxxxxx>]

Dear Rongxin Yin,

Everything Richard says below is correct.  

In addition, I suggest that it is not reasonable to attempt to match
actual energy usage with Energy Plus predicted usage on such a small
time increment.

There are too many variables which affect a real HVAC system that are
not possible to account for in a computer model.  If I got a plus /
minus 10% agreement between real and predicted energy MONTHLY, I would
be VERY happy!

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad
<RRaustad@...> wrote:
>
> For the first hour of operation:
> 
> 1) does the chiller part-load ratio match for the real vs tested data?
> 2) does the return water temperature match for the real vs tested data?
> 3) does the outdoor temperature match for the real vs tested data?
> 4) does changing the loop volume change these results?
> 
> Rongxin Yin wrote:
> >
> > Hi All,
> >
> > Resently i did some calibration to get the baseline model by means of 
> > comparing the real tested data to the simulated output results.
then i 
> > found the simulated electrical consumption of the chiller was much 
> > higher than the real tested data at the beginning of the operation 
> > hours. and about one hour later, the load profile would be normal as 
> > the real data. So i am not sure whether this result is ok or not.
Does 
> > anyone meet the same question?
> >
> > Thanks,
> > Rongxin
> >
> > __________________________________________________________
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> > [Non-text portions of this message have been removed]
> >
> >  
> 
> -- 
> Richard A. Raustad
> Senior Research Engineer
> Florida Solar Energy Center
> University of Central Florida
> 1679 Clearlake Road
> Cocoa, FL  32922-5703
> Phone:   (321) 638-1454
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