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[EnergyPlus_Support] Re: Air flow from one zone to another: extraction to return air duct
There is no RA flow rate in zone 1, because I use a Fan:ZoneExhaust in this zone. By doing
so, the flow balance in zone 1 is correct.
To keep things simple, I first wanted to delete the Fan:ZoneExhaust in zone 1 and use the
corresponding RA flow rate from this zone in the return duct, but this is thermally
incorrect: the air passing from zone 1 first heats zone 2 and then the air from zone 2
heats zone 3: the RA from zone 3 will be cooler than the RA from zone 1..
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad <RRaustad@...> wrote:
>
> Wait a minute, if the air from zone 1 is moved to zone 2 and 3 using
> mixing objects, isn't there a RA flow rate on zone 1 already?
>
> Richard Raustad wrote:
> >
> > How about trying to connect the outlet node of the Fan:ZoneExhaust to a
> > new inlet node in zone 1 (and disregard the flow imbalance warnings in
> > zone 3). Does this give you a RA flow rate in zone 1?
> >
> > joskenzy wrote:
> > >
> > >
> > > No I haven't, but I don't really see how this could solve my problem:
> > >
> > > 1) If I use a Fan:ZoneExhaust in zone 3, the air flow balance for this
> > > zone will fail (there is
> > > no supply air, no return air, only exhaust air) ? I believe ZoneMixing
> > > is not taken into
> > > account in the air flow balance?
> > >
> > > 2) If I connect the Fan:ZoneExhaust in zone 3 to the air inlet node of
> > > my heat exhanger
> > > (HeatExchanger:Dessicant:BalancedFlow), than I cannot connect the
> > > return air duct of the
> > > other zones (there are 14 other VAV-zones in my building, apart from
> > > the 3 zones
> > > considered in my example) to this HX ?
> > >
> > > Thank you anyway, I appreciate your effort!
> > >
> > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> > <mailto:EnergyPlus_Support%40yahoogroups.com>
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>, Richard Raustad
> > > <RRaustad@> wrote:
> > > >
> > > > Have you tried connecting the outlet of the Fan:ZoneExhaust in zone
> > > 3 to
> > > > the heat exchanger ?
> > > >
> > > > joskenzy wrote:
> > > > >
> > > > > Could anyone help me implement the following ventilation concept:
> > > > >
> > > > > Say the building has 3 zones: treated air (SingleDuct:VAV:Reheat) is
> > > > > injected in the first zone. The same air flow rate passes from the
> > > > > first, through the second and into the third zone.
> > > > >
> > > > > There is no treated air injected in the second or the third zone.
> > > > >
> > > > > An air flow rate equal to the injection rate in zone 1 is extracted
> > > > > from zone 3.
> > > > >
> > > > > Normally, one would suggest to supply air to zone 1 and to use a
> > > > > Fan:ZoneExhaust to balance air flows. Using ZoneMixing, you can
> > > > > simulate air flowing from zone 1 to zone 2, and air flowing from
> > zone
> > > > > 2 to zone 3.
> > > > >
> > > > > However (now comes the hard part): the building has other
> > VAV-balanced
> > > > > zones, and I want to add the extracted air from zone 3 to the return
> > > > > duct of the other zones because the return air is used in a heat-
> > > > > exchanger.
> > > > >
> > > > > So for zone 3, I have an air flow entering the zone because of the
> > > > > ZoneMixing (zone 2 as source zone), but how can I add the replaced
> > > > > zone air to the air in the return duct?
> > > > >
> > > > > I looked at the manual and at previous topics here, but I only found
> > > > > that ZoneMixing adds air to a zone, while supposing an equal
> > flow rate
> > > > > has left the zone (without knowing where the air went)..
> > > > >
> > > > > I would really appreciate your help!
> > > > >
> > > > >
> > > >
> > > > --
> > > > 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
> > <http://www.fsec.ucf.edu> <http://www.fsec.ucf.edu
> > <http://www.fsec.ucf.edu>>
> > > >
> > > > UCF - From Promise to Prominence: Celebrating 40 Years
> > > >
> > >
> > >
> >
> > --
> > 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 <http://www.fsec.ucf.edu>
> >
> > UCF - From Promise to Prominence: Celebrating 40 Years
> >
> >
>
> --
> 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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