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Re: [EnergyPlus_Support] Fwd: Re: Constant Air Volume with Heat Recovery?



Check the cooling coil and see if it turns on. If the heating coil then 
heats the cold air, something is wrong with the control.

What type of set point manager is used for each coil? Should be single 
zone heating and single zone cooling for the heating and cooling coils, 
respectively.
What is the minimum and maximum temperature used for each set point 
manager? Leave a wide range on min/max and let the set point managers 
choose the set point.

Start with the cooling coil inlet node and compare that temperature to 
the cooling coil outlet node "set point temperature". If the cooling 
coil inlet temperature is above the set point, the cooling coil should 
turn on. Then compare the outlet temperature of the cooling coil, or 
inlet temperature of the heating coil, to the heating coil outlet node 
set point temperature. If the heating coil inlet temperature is below 
the set point, the heating coil should turn on. The heating coil "set 
point temperature" should always be less than or equal to the cooling 
coil "set point temperature". If they are not, check what the settings 
are to the min/max values in the set point managers.

anarui.oliveira wrote:
>
> ???
> Although it determines different temperatures at the outlet of the
> cooling and heating coil, the supply temperature seems to always
> follow the "last" coil (heating coil) temperature, ignoring whether
> there is a cooling or a heating load?...
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx 
> <mailto:EnergyPlus_Support%40yahoogroups.com>, "anarui.oliveira"
> <anarui.oliveira@...> wrote:
>
> Thank you both.
>
> Can you help me understand how the setpoint managers (don't mention
> control nodes nor temperature setpoints) relate to the controllers
> and which setpoints these objects are actually referring to?
>
> Also for the outside air controllers, to which setpoints they are
> referring? If I want to force constant outside airflow, can I delete
> these objects?
>
> Where can I define that the heat exchanger should be bypassed if
> there is no advantage in that heat exchange, given the outside an
> return air temperatures?
>
> Thanks again,
> Ana.
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx 
> <mailto:EnergyPlus_Support%40yahoogroups.com>, Fred Buhl <wfbuhl@>
> wrote:
> >
> > Thanks Richard; that's a good one to look at also.
> >
> > Fred
> >
> > Richard Raustad wrote:
> > > Try 5ZoneWaterSystems as an example. You would have a Primary Air
> Loop
> > > for each zone and would control the coils differently. Use the
> set point
> > > managers for single zone cooling (control node is outlet node of
> chilled
> > > water coil) and single zone heating (control node is outlet node
> of hot
> > > water coil) to control the air loop water coils. You will not
> need the
> > > reheat coils shown in this example. You could add heat recovery
> to the
> > > outside air system for each primary air loop.
> > >
> > > anarui.oliveira wrote:
> > >
> > >> Thanks.
> > >> I've been looking at those unitary systems, but do they really
> allow
> > >> me to replace the coils? They show up as necessary inputs and as
> > >> those specific types of coils in the definition of unitary
> equipments?
> > >> Ana.
> > >>
> > >> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx 
> <mailto:EnergyPlus_Support%40yahoogroups.com>
> > >> <mailto:EnergyPlus_Support%40yahoogroups.com>, Fred Buhl
> <wfbuhl@>
> > >> wrote:
> > >>
> > >>> It sounds sort of like a single zone system - there's examples
> of
> > >>> packaged single zone systems
> > >>> (for instance SmOffPSZ). You'd have to repalce the DX and Gas
> coils
> > >>>
> > >> with
> > >>
> > >>> chilled and hot water
> > >>> coils. And add heat recovery.
> > >>>
> > >>> Fred Buhl
> > >>>
> > >>> anarui.oliveira wrote:
> > >>>
> > >>>> Hello, everyone.
> > >>>>
> > >>>> I can't seem to find a model in E+ that corresponds to:
> > >>>> - a dedicated AHU (with heat recovery) serving only one zone,
> > >>>> - with constant volumetric air flow (always 100% outside air)
> > >>>> - using a chilled water loop and a hot water loop for air
> > >>>>
> > >> conditioning
> > >>
> > >>>> - where the zone temperature control is done directly and
> > >>>>
> > >> uniquely by
> > >>
> > >>>> turning the coils on/off at the System level (AHU), rather then
> > >>>> changing the air flow or doing reheat/recool at zone level.
> > >>>>
> > >>>> Can I include Heat Recovery in any HVAC objects, other than the
> > >>>>
> > >> system
> > >>
> > >>>> level AHUs, to solve this issue with a zone level equipment or
> > >>>>
> > >> other
> > >>
> > >>>> simplification?
> > >>>>
> > >>>> All ideas are welcome.
> > >>>> Regards,
> > >>>> Ana Rui.
> > >>>>
> > >>>>
> > >>>> ------------------------------------
> > >>>>
> > >>>> The primary EnergyPlus web site is found at:
> > >>>> http://www.energyplus.gov <http://www.energyplus.gov> 
> <http://www.energyplus.gov <http://www.energyplus.gov>>
> > >>>>
> > >>>> The group web site is:
> > >>>> http://groups.yahoo.com/group/EnergyPlus_Support/ 
> <http://groups.yahoo.com/group/EnergyPlus_Support/>
> > >>>>
> > >> <http://groups.yahoo.com/group/EnergyPlus_Support/ 
> <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
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>
> > >>
> > >
> > >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> --- End forwarded message ---
>
>  

-- 
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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