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[EnergyPlus_Support] Re: Output Variable to Calculate the Zone Load Requirements



Thank you very much for the responce prof. Raustad. 
So if my understanding is correct the Zone/Sys Sensible Cooling & Heating Energy can be used to calculate the direct energy impacts of a system in a zone(for example the energy effects of a shading system)without taking into account the wheather conditions. The direct effects of a "measure" (shading, U-Value,Glazing type, etc) on a system-zone level and not on a complete whole building/space analysis. 
In an energy simulation where the target is to calculate the energy loads on a whole building scale, the climate is an important factor and should be taken into account. The Ideal Load total or zone total Heating and Cooling should be requested.


--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad <RRaustad@...> wrote:
>
> One of the best ways to understand this is to report the zone temp, 
> humidity ratio, and enthalpy along with the zone inlet node temp, 
> humidity ratio, and enthalpy. Also report the zone inlet node mass flow 
> rate.
> 
> You can then calculate the zone energy entering the zone through the 
> zone inlet node. Q = Mdot(deltaH)
> 
> Zone/Sys Sensible Cooling or Heating  Energy only report what enters the 
> zone through the zone inlet node. It does not include any effects of 
> outdoor air or fan heat.
> 
> The ideal loads total heating and ideal loads zone total heating show 
> the same value and is an enthalpic calculation (includes impact of 
> moisture difference between zone inlet node and zone node), the ideal 
> loads sensible variables only show the impact of temperature difference 
> between the zone inlet node and zone node.
> 
> It depends on what your goal is as to which report variables to use. Do 
> you want to know the energy impacts of outdoor air? Or just the energy 
> required to meet the standard zone loads?
> 
> On 10/4/2012 1:53 AM, kontadakisantonios wrote:
> > Hello,
> > I usually use a HVACTemplate:Zone:IdealLoadsAirSystem in order to calculte the annual requirements for heating and cooling of a zone.
> > In the Output:Variable there are several variables from which you can take the Energy loads:
> >
> > #A#"Zone/Sys Sensible Cooling Energy" & :Zone/Sys Sensible Heating Energy";
> >
> > #B1# "Ideal Loads Total Heating Energy" & "Ideal Loads Total Cooling Energy";
> > #B2# "Ideal Loads Sensible Cooling Energy" & "Ideal Loads Sensible Heating Energy"
> >
> > #C1# "Ideal Loads Zone Total Heating Energy" & "Ideal Loads Zone Total Cooling Energy"
> > #C2# "Ideal Loads Zone Sensible Heating Energy" & "Ideal Loads Zone Sensible Cooling Energy"
> >
> > Those three output sets give different Annual/Summary loads (J), for example in an South oriented office room of 18.36 m2 located in Athens-Greece the annual loads for heating and cooling are:
> > #A#  Zone/Sys Sensible_Heating=324957402J, Cooling= 3557071988J
> > #B1# IdealLoads Total_ Heating=404805597.1J, Cooling=4261318764J
> > #B2# IdealLoads Sensible_Heating=326646181.2J, Cooling=3562938318J
> > #C1# IdealLoads Zone Total_Heating=404807810.5J, Cooling=4261320977J
> > #C2# IdealLoads Zone Sensible_Heating=326645932.9J, Cooling=3562934397J
> >
> > The main question is:
> > "In order to calculate the annual or monthly requirements of a space for heating and cooling when using an ideal Load HVAC System which output set i request?"
> > Please if possible explain the difference between the output viarable sets and when we use them.
> >
> > Any help to better understand E+ would be appreciated
> > Thank you in advance very much
> > Antonis.
> >
> >
> >
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> 
> -- 
> 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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