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[EnergyPlus_Support] Re: The wierd results of cooling load rate.
Dear Michael:
Thank you very much for your reminding. I have found that it is the
internal mass and the massive building envelope made the difference. I
still have several questions.
1. The total internal heat gains are exactly the same for both of these
two models. It should be so because they have the same occupancy,
lighting and equipment schedule. What puzzled me is for these two
models, they also have the same infiltration volume flow rate, but the
Infiltration Sensible Heat Gain is not the same to each other. Even
though the difference is not too big, it still doesn't make sense to me.
2. As for the Mechanical Ventilation Cooling Rate Increase, I also have
the same question. The two models have the same Outside Air Volume Flow
Rate, but the Mechanical Ventilation Cooling Rate Increase are different
from each other ( More Increase with more Set forward degrees). The
difference is kind of significant.
3. As for the Windows Heat Gains, I can not the slight difference
between this two models.
Thank you very much.
Wei
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte"
<mjwitte@...> wrote:
>
> Thermal mass effects could result in a higher cooling rate for the
entire
> occupied period. Compare the sum of the cooling load across the
entire 24 hour
> period. You should see that the 24-hr cooling load is less in the
night
> setback case.
>
> Other factors to consider in such a comparison: does the HVAC system
have an
> outside air inlet? If so, it the fan continuous or cycling? Are you
comparing
> "Zone/Sys Sensible Cooling . . ." or the coil load?
>
> If you are not able to explain this, please upload the two input files
to the
> files area in the yahoo group or send as a zipped attachment to
energyplus-
> support@...
>
> Mike
>
>
> On 23 Apr 2007 at 22:15, xjtu.guowei wrote:
>
> > Dear All:
> >
> > I have run the simulation for two models. The only difference
between
> > them is the thermostat schedule.
> > The first one is 75F(Cooling) for the all time during the day; the
> > other one is 75F(6:00AM-5:00PM)and 80F (the rest time of the day),
> > which is sort of like nightsetback. People is in the zone from
7AM-5PM.
> > From my analysis, for the second model,the cooling load rate will be
> > going up around 7Am and go back to almost the same values as the
first
> > model.
> >
> > But from the results I got, during the period of 7AM-5PM, the second
> > model's cooling load rate is about 20%-15% highter than the first
> > model, which didn't make any sense to me. I am wondering if there is
> > anything wrong with E+ or my model? Please help me to figure it out.
> > By the way, I checked the heating load rate which made sense to me.
> >
> > Thank you in advance.
> >
> > Wei
> >
> >
> >
> > 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@...
>
[Non-text portions of this message have been removed]
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