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[EnergyPlus_Support] Re: Air handler Heating coil operates in the summer

Dear Don,

Two different SET POINT MANAGER:SCHEDULED objects refer to the same
compact schedule set for 12.8C at all times.  Both SET POINT
MANAGER:SCHEDULEDs use "NodeOut_Air_AH1" as the set point node.

It is a draw through configuration, so you're correct re: making
account for the fan heat, however here is a typical result for one
time interval (in order as the air moves through the air handler):

Mixed air Temp:   66.3F
CC leaving temp:  49.8F
HC leaving temp:  50.8F (HC warms the air 1F)
Fan leaving temp: 55.0F (Fan warms the air 4.2F)



--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Don Shirey <shirey@...> wrote:
>
> Sounds like the cooling coil is operating to overcome the cooling load 
> and the supply air fan heat.
> 
> Where are you setting your setpoint temperatures?  At the outlet of the 
> cooling and heating nodes?  What type of setpoint managers are you
using?
> 
> JV Dirkes II wrote:
> > Dear EPlus Forum,
> >
> > My model has an air loop with a single branch as shown below.  The
> > heating and cooling coils are both set to:
> > a) use a constant 55F / 12.8C discharge temperature,
> > b) measured at the identical node (the outlet node for the AHU).
> >
> > During the summer design day operating hours, the temperature leaving
> > the cooling coil is a few tenths of a degree C below what is needed,
> > so the heating coil operates to boost the temp.  This, of course,
> > causes additional energy use.  What causes it and how can I
elimimate it?
> >
> > Thanks in advance!
> >
> > BRANCH,
> > Branch_AirLoop_AH1,
> > 11.3268,
> > OUTSIDE AIR SYSTEM,
> > OASystem_AH1,
> > NodeIn_RA_AH1,
> > NodeOut_MA_AH1,
> > PASSIVE,
> > COIL:WATER:COOLING,
> > ClgCoil_AH1,
> > NodeOut_MA_AH1,
> > NodeOut_ClgCoilAir_AH1,
> > PASSIVE,
> > COIL:GAS:HEATING,
> > HtgCoil_AH1,
> > NodeOut_ClgCoilAir_AH1,
> > NodeOut_HtgCoilAir_AH1,
> > PASSIVE,
> > FAN:SIMPLE:CONSTVOLUME,
> > SFan_AH1,
> > NodeOut_HtgCoilAir_AH1,
> > NodeOut_Air_AH1,
> > ACTIVE;
> >
>



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