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[EnergyPlus_Support] Re: Minimum Input to calculate load requirements
Hi Richard,
Thanks for you help! I will look into your suggestions.
You are right, I am not look for true minimum, but the "minimum" to
calculate cooling load for a single room. However, since cooling load
is sensible + latent load, does that mean Purchased Air will NOT give
me a good estimate for the load need for that room? Or does it still
give me a reasonable estimate?
What kind of HVAC object would you suggest for an "optimal" load
determination. That is, not so much a real system, but this is the
best you can expect to achieve. I want to start by playing with an
"ideal" system and then get more and more realistic.
Thanks again!
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad
<RRaustad@...> wrote:
>
> 1) This seems like a good "minimum" requirement for what you intend to
> do. If you only wanted to look at sun angles (I believe there is an
> example file called minimal.idf that does this), you would not even
need
> to define the building constructs, so it depends on what your
simulation
> results need to be to determine what the minimal required input is.
> 2) Purchased air is an ideal cooling or heating system with unlimited
> capacity. You can use this object to get an idea of zone sensible
loads.
> It's not a good choice to determine the zone latent loads. And you will
> most likely need to replace the purchased air object with an HVAC
system
> to see how actual cooling load vary with real systems.
> 3) The sensible load predicted tells you what the thermostat thinks the
> load is to get the zone back to the set point. If the zone meets the
> setpoint, this is a good indicator of sensible load. There are other
> report variables that could be used, for example the purchased air
> object has its own report variables, See the InputOutput Reference and
> look at the section called Purchased Air Outputs. Report out Purchased
> Air Sensible Cooling Rate and compare it to Zone/Sys Sensible Load
> Predicted. These should be nearly the same values.
> 4) Most everything in the simulation affects the cooling load. If you
> are asking how the zone cooling load is calculated, see equation 2 in
> the Engineering Reference.
>
> noplayer101 wrote:
> >
> > Hi Guys,
> >
> > I am new to EnergyPlus and in general the whole HVAC world.
> >
> > As a first step I just wanted to implement a simple single zone
> > building (i.e rectangular box) and just determine the cooling load
> > required for it.
> >
> > So I 1)Defined just the building with 6 surfaces, 2) added Purchased
> > Air (I assumed it was an necessary input do get the cooling load),
> > 3)Set a Dual Setpoint with Deadband, and 4) Outputed Sensible Load
> > Predicted.
> >
> > I run the simulation with a weather file for a year (reporting daily).
> >
> > First, am a correct to assume this is the minimum setup needed.
> > Second, what exactly is purchased air. The help file's definition is
> > a bit confusing to me. Lastly, am I viewing the correct output for
> > the cooling load (also where can I find what factor determine it's
> > value i.e outside temp, surface material, etc)
> >
> > Thank you very much! :-)
> >
> >
>
> --
> 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
> Fax: (321) 638-1439 or 1010
> Visit our web site at: http://www.fsec.ucf.edu
>
> UCF - From Promise to Prominence: Celebrating 40 Years
>
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