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Re: [EnergyPlus_Support] Re: Air flow from one zone to another: extraction to return air duct



No, do not use a new AirTerminal. Just define an inlet and exhaust node 
name for zone 2 and an inlet node name for zone 3 the same way you did 
for zone 1.The name of the inlet node in zone 2 is the same as the 
exhaust fan outlet node name from zone 1. Use the exhaust node name from 
zone 2 as the exhaust fan inlet node name and the inlet node name in 
zone 3 as the exhaust fan outlet node name for the exhaust fan that 
connects zone 2 and 3.. Yes, the node names define the connection. 
Again, I'm not sure this will work, but I can't think of anything else 
other than deleting the exhaust fan in zone 1 and using the RA from zone 
1 to increase the flow through the HX. If you choose to delete the 
exhaust fan in zone 1, ignore the warning of flow imbalance in zone 1. 
Make sure you check the RA, SA, and EA flow rates in zone 1, 2 and 3 no 
matter which method you use.

  ZoneHVAC:EquipmentConnections,
    RESISTIVE ZONE,          !- Zone Name
    Zone1Equipment,          !- Zone Conditioning Equipment List Name
    Zone1Inlets,             !- Zone Air Inlet Node or NodeList Name
    ,                        !- Zone Air Exhaust Node or NodeList Name
    Zone 1 Node,             !- Zone Air Node Name
    Zone 1 Outlet Node;      !- Zone Return Air Node Name

  NodeList,
    Zone1Inlets,             !- Name
    Zone 1 Inlet Node;       !- Node 1 Name


joskenzy wrote:
>
> This is probably not a smart question, but I am new to EnergyPlus so 
> forgive me for
> asking: how can i connect the outlet node of an exhaust fan to a zone 
> node?
>
> I am not using the AirflowNetwork, so I don't have air distribution 
> nodes in my zones...
> Do you mean I have to define a new 
> AirTerminal(SingleDuct:Uncontrolled), and use the
> outlet node of the exhaust fan as the air inlet node of this 
> AirTerminal-object? I thought
> this was just a matter of giving nodes a name, I didn't think they 
> were connected just by
> using the same name?
>
> Thanks again..
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx 
> <mailto:EnergyPlus_Support%40yahoogroups.com>, Richard Raustad 
> <RRaustad@...> wrote:
> >
> > Yes, that would be thermally incorrect, but at least you would have the
> > air balance on the RA nodes. You just want to get as close as possible
> > with the tools you have available. The only other thing I can think of
> > is to use a zone exhaust in zone 1 and connect the exhaust fan outlet
> > node to an inlet node in zone 2, and the zone exhaust fan outlet from
> > zone 2 to an inlet node in zone 3. I have tried this before but can't
> > recall what happened. If that works, you would not have to use the
> > mixing objects. There would of course be fan heat involved in moving 
> the
> > air so adjust the fan power down as far as you can go.
> >
> > joskenzy wrote:
> > >
> > > 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 
> <mailto:EnergyPlus_Support%40yahoogroups.com>
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>, 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>
> > > > > <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>>
> > > > > <http://www.fsec.ucf.edu <http://www.fsec.ucf.edu> 
> <http://www.fsec.ucf.edu <http://www.fsec.ucf.edu>>>
> > > <http://www.fsec.ucf.edu <http://www.fsec.ucf.edu> 
> <http://www.fsec.ucf.edu <http://www.fsec.ucf.edu>>
> > > > > <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>
> > > <http://www.fsec.ucf.edu <http://www.fsec.ucf.edu>> 
> <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> <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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