[EnergyPlus_Support] Re: (Still) airflow balances!

["anarui.oliveira" <anarui.oliveira@xxxxxxxxx>]

Zone 1 gets its supply air from a CAV central system with heat 
recovery.
Part of the airflow supplied to Zone 1 is collected again and 
becomes return airflow, passing through the central heat exchanger 
before being discarded. The remaining airflow is supposed to pass to 
the adjacent Zone 2 simply by pressure difference.
In Zone 2 there is just an exhaust fan (in the project), which keeps 
this zone in depression and forces air renovation.

Thank you for the patience,
Ana.

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Fred Buhl <wfbuhl@...> 
wrote:
>
> Ana,
> 
> I guess we don't understand what you are trying to simulate. You 
have 2 
> zones,
> one of which gets supply air. Just tell us what happens to this 
air after it
> is supplied to the 1st zone. Don't explain it in terms of 
EnergyPlus, 
> just tell us
> what you actually want to happen. Are there any real exhaust fans, 
or 
> did they get
> introduced as an attempt to model the actual situation? Just 
explain 
> what the system
> is that you are attempting to model (maybe you did this already, 
but 
> please do it again).
> 
> Fred Buhl
> 
> anarui.oliveira wrote:
> > Thank you all for your previous answers, and please tolerate my 
> > insistence...
> > I see your point about balancing airflows in the source zone, 
and I 
> > think I've got that covered.
> >
> > ...But, returning to a simple example of 2 zones:
> > - one conditioned (Zone 1), with forced supply air (which can be 
> > modelled by E+ system and zone level objects)
> > - and another unconditioned (Zone 2), which:
> >    - receives some airflow by depression from the conditioned 
zone 
> > (here I would use a Mixing object(source Zone 1, target Zone 2), 
and 
> > an exhaust fan in Zone 1 (a plain E+ Exhaust fan, no tricks), 
just 
> > to make sure that the source zone also feels the effect of 
losing 
> > that amount of conditioned air)
> >    - but then in the unconditioned zone, the HVAC project says 
there 
> > will also be a regular, forced exhaust airflow (although there 
is no 
> > mechanical air supply directly to this zone), and it is this 
part, 
> > this exhaust... this balance at the unconditioned zone (which is 
the 
> > target zone for the mixing object), that I don't quite see how 
to 
> > implement...
> >    - and should I care?... It's not very clear to me, but I 
seems 
> > that if I do force the exhaust of that amount of air, the 
> > unconditioned zone will continuosly lose some its partially 
> > conditioned air (energy), at the same time as it receives new 
air 
> > from the adjacent zone, while if I don't balance it, it seems it 
> > continuosly accumulates warm air and only loses heat through the 
> > envelope?...
> >
> > Sorry, I have the feeling I'm not making myself very clear, 
but...
> > ... again, any additional hint would be greatly appreciated!
> >
> > Ana.
> >
> >
> > ------------------------------------
> >
> > 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.
> >
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under the Documentation link and press the "search" button.
> > Yahoo! Groups Links
> >
> >
> >
> >
>



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