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[EnergyPlus_Support] Re: Air Flow between Zones
If I use the system that is described below, is it possible to use
the air that is exhausted by the adjacent zones to preheat the air
that is send to the central zone (with a heat exchanger/ heat
recovery)
thanks,
Nina.
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte"
<mjwitte@...> wrote:
>
> Airflownetwork has limitations which prevent it from being used for
this
> application. This can be modeled as follows:
>
> 1. In the central zone, add a ZONE EXHAUST FAN with a flow rate
equal to the
> amount of air which passes to the adjacent zones. This will
balance the
> airflows for the central zone (return = supply - exhaust). Why put
the exhaust
> (extractioni fan) in the central zone? Because the air loop
simulation needs
> to know that some quantity of air is leaving the central zone
through a path
> that is not the return duct. It does not matter if the air leaves
through an
> exhaust fan, a door to and adjacent zone, or whatever.
>
> 2. Use MIXING objects to move air from the central zone to the
adjacent zones.
> So, you may ask, why no exhaust fan in the adjacent zones? When
MIXING adds
> air to a zone, it assumes that an equal amount of air has left the
zone. It
> does not matter where the air went. So, the "extraction" of air
from the
> adjacent zones is already modeled. The extractino fan power can be
accounted
> for in the central zone exhaust fan.
>
> Note that the air loop simulation is not aware of the MIXING
objects in terms
> of balancing airflow. It is the user's responsbility to make sure
that the
> flow rates are balanced.
>
> Mike
>
>
> On 17 Jan 2008 at 13:53, Filipe madureira wrote:
>
> > Hi all,
> >
> >
> >
> > I working in a commercial building which has the following
characteristics:
> >
> >
> >
> > 1. A central zone rounded by several adjacent zones
> >
> > 2. The adjacent zones communicate with central zone through
doors.
> >
> > 3. A central system (CV or VAV, it isn' t defined yet)
provides
> > treated fresh (outside) air to central zone. The air flow rate
accounts
> > with the necessary fresh air to central and adjacent zones
> >
> > 4. It is planned that adjacent zones have negative
pressure in a way that
> > the compensating air flow rate come from central zone through the
door (an
> > extraction fan will exhaust an air flow rate equal to the fresh
air needed in
> > the zone ). Adjacent zones will also have a zone forced air unit
to provide the
> > necessary local heating or cooling.
> >
> >
> >
> > Is it possible to simulate this situation? I'm not sure if I can
do this
> > with Airflow NetWork .
> >
> >
> >
> > One of my issues is that in the central air loop:
> >
> > Return air flow rate + Zone exhaust Flow rate= Supply air flow
rate
> >
> >
> >
> > so I don' t know if air loop could take in account the air flow
rate that
> > passes to adjacent zones
> >
> >
> >
> > Thanks in advance for your help
> >
> > Best Regards
> >
> >
> >
> > Filipe Madureira
> >
> > Tel: +351 919 293 876 | E-mail: filipe.madureira@...
> >
> > __________________________________________________________________
> >
> > FluidInova, Engenharia de Fluidos, SA
> >
> > TECMAIA - Parque de Ciência e Tecnologia da Maia
> >
> > Rua Engº Frederico Ulrich, nº 2650 | 4470-605 Moreira da Maia |
Portugal
> >
> >
> > Tel: (351) 229 408 265 | Fax: (351) 229 408 266
> >
> > E-mail: <mailto:geral@...> geral@... | Web:
> > <http://www.fluidinova.pt/> http://www.fluidinova.pt/
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> > 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@...
>
------------------------------------
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