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Re: [EnergyPlus_Support] Re: Condenser air inlet node and unbalanced air flow warnings
Thank you, Ana Rui. I had checked the system node flow report for system-1
and the zones attached to system-1. The flow rate of the outside air
delivered by system-1 is the same as the total amount of air exhausted. And
the return and relief nodes report zero air flow as expected. The error
message shows that this error only occurs at the begining of the simulation
(the first hour). I have no idea what caused this.
On Mon, Mar 31, 2008 at 2:07 AM, anarui.oliveira <anarui.oliveira@xxxxxxxxx>
wrote:
> I'm not an expert, but I think it's usually useful to report "System
> Node VolFlowRate" at the relevant zone and system inlets/outlets to
> understand what is happening.
> Have you checked if the Air mixing box in the air loop is
> recirculating some of what was supposed to be the return/relief
> airflow (I suggest it because I'm having a similar problem on that
> account).
>
> Ana Rui.
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx<EnergyPlus_Support%40yahoogroups.com>,
> "w_jiang78"
> <antixs.antixs@...> wrote:
> >
> > Hi,
> >
> > I am trying to model a PTAC system and a separate outside air
> system
> > (system-1) used for space ventilation. I also simulated exhuast fan
> > for each space. Two types of warnings occured during simulation
> (the
> > second warning repeated for hundreds of times).
> >
> > (1)In Air Primary Loop System-1 there is unbalanced exhaust air
> flow.
> > ** ~~~ ** During Warmup, Occurrence info=DULUTH_MN_USA
> > HEATING 99.6% CONDITIONS, 01/21 00:00 - 00:15
> > ** ~~~ ** Unless there is balancing infiltration /
> > ventilation air flow, this will result in
> > ** ~~~ ** load due to induced outside air being neglected
> in
> > the simulation.
> >
> > In the model, system-1 was sized using flow/system and exhaust air
> > flow rate for each zone was input as hard velues(the sum of exhaust
> > air flow for all zones equals to the supply air flow rate of system-
> > 1). All fans run continuously. Why does this error occur even
> though
> > the flow rates are input as hard values and they match with each
> > other?
> >
> > (2) COIL:DX:COOLINGBYPASSFACTOREMPIRICAL "System-1 COOLING COIL" -
> > Air-cooled condenser inlet dry-bulb temperature below 0 C. Outdoor
> > dry-bulb temperature = -7.20
> > ** ~~~ ** ... Occurrence info = DULUTH MN USA TMY2-14913
> > WMO#=727450, 01/20 21:08 - 21:09
> >
> > In the model, the cooling/heating priority is 1 for outside air
> > system, 2 for PTAC and 3 for exhaust fan. Any insights on what
> might
> > cause this?
> >
> > Thank you for your help.
> >
> > Ashley
> >
>
>
>
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