[esp-r] Re: air quality assessment for room with natural ventilation

Wed Nov 7 12:10:24 GMT 2007

... and, as an afterthought, for those of the community that can read German, there are a few studies on the topic available on the net:

	http://www.uni-kassel.de/fb6/bpy/de/index.html

Section "Luftwechsel" (at the bottom of the page)
Achim

> -----Original Message-----
> From: esp-r-bounces at lists.strath.ac.uk [mailto:esp-r-
> bounces at lists.strath.ac.uk] On Behalf Of Geissler Achim
> Sent: Wednesday, November 07, 2007 1:02 PM
> To: Jeremy Cockroft; esp-r at lists.strath.ac.uk
> Subject: [esp-r] Re: air quality assessment for room with natural
> ventilation
> 
> ... I seem to remember that Comis was capable. However, one needed to
> define the "Stack" in the one-sided-ventilated-zone (temperature
> difference over the height of the zone). And, one could define two
> different external nodes for the top / bottom opening to the outside with
> two different sets of Cp-values ...
> Maybe stacking a few zones for one actual space and then having inlet and
> outlet in different stacked zones could help. For this type of model I am
> always a bit queasy in regard to long wave radiation ... Gunter did
> mention a cooled ceiling ...
> Regards,
> Achim
> 
> > -----Original Message-----
> > From: esp-r-bounces at lists.strath.ac.uk [mailto:esp-r-
> > bounces at lists.strath.ac.uk] On Behalf Of Jeremy Cockroft
> > Sent: Wednesday, November 07, 2007 12:29 PM
> > To: esp-r at lists.strath.ac.uk
> > Subject: [esp-r] Re: air quality assessment for room with natural
> > ventilation
> >
> > I think the question is: does ESP-r have the capability to model bi-
> > directional airflow through an open window into a zone that is
> > substantially sealed from other zones in the building.  A common
> question
> > and the answer (short of invoking the CFD domain) is no - the bi-
> > directional flow component was originally developed to model tall
> vertical
> > openings, typically doors, between zones, with bouyancy driven airflows
> in
> > either direction.  It does not take account of wind turbulence effects
> > that will drive bi-directional airflow at an open window, which is what
> is
> > missing for this application.  Modelling as two orifices won't help -
> they
> > will both see the same external pressure node.
> >
> > This topic has been researched (I co-authored a paper on this in the
> '70s)
> > but to my knowledge no-one has coded such functionality into any zonal
> > dynamic modelling tool ... but I might be mistaken ...
> >
> > Jeremy
> >
> > -----Original Message-----
> > From: esp-r-bounces at lists.strath.ac.uk [mailto:esp-r-
> > bounces at lists.strath.ac.uk] On Behalf Of Aizaz Samuel
> > Sent: 07 November 2007 10:25
> > To: Pueltz, Gunter
> > Cc: esp-r at lists.strath.ac.uk
> > Subject: [esp-r] Re: air quality assessment for room with natural
> > ventilation
> >
> > Contaminant modelling works with bi-directional flow components just as
> > with other components and you probably will end up with more CO2 going
> out
> > of the zone as coming into it provided there are local CO2 sources
> > (metabolic rates
> > maybe) defined within the zone. I have never made a model with bi-
> > directional components though and would fall back on Jon's
> recommendation
> > if it does not work.
> >
> > There is no provision yet to show the mass flow of contaminant along
> each
> > flow path because only concentration for each node is stored in the
> > results library. It should be possible to obtain this information by
> post
> > processing node concentrations and air flow rates
> >
> > -Aizaz
> >
> > On Wednesday 07 November 2007 07:06, Jon Hand wrote:
> > > A bi-directional component might be replace by two common orifice
> > > components (suitably placed to represent the upper and lower portion
> > > of the window).
> > > That should allow the CO2 to 'see' the flow in.
> > >
> > > Whether the CO2 bookkeepping could be revised to allow it to track
> > > both paths of a bi-directional component is something Aizaz might
> > > advise on.
> > >
> > > -Jon
> > >
> > >
> > > -----Original Message-----
> > > From: Pueltz, Gunter [mailto:Gunter.Pueltz at MuellerBBM.de]
> > > Sent: Wed 11/7/2007 6:38 AM
> > > To: 'esp-r at lists.strath.ac.uk'
> > > Cc: Aizaz Samuel; Jon Hand
> > > Subject: air quality assessment for room with natural ventilation
> > >
> > > Dear ESP-r developers,
> > >
> > > currently I have a simulation job for an office building, which shows
> > > only natural ventilation (NO mechanical ventilation) by openable
> windows.
> > > In Summer the rooms are cooled by chilled ceilings.
> > >
> > > Now my client wants infos about the indoor air quality, which can be
> > > obtained by the window ventilation.
> > > I do know, that ESP-r shows the ability to calculate CO2-
> concentrations.
> > > This is a good facility to assess indoor air quality, as CO2 is
> > > representing air quality very well.
> > > But my last knowledge of this contaminant calculations in ESP-r was,
> > > that for a flow component with BI-DIRECTIONAL air flow (typical for an
> > > open
> > > window)
> > > only the net-flow is taken into account for the CO2-balance in ESP-r.
> > > The net-flow of an open window of one single room always is zero - so
> > > this approach do not work for a room with single-sided window
> > > ventilation.
> > > Or - in other words - the reduction of CO2-concentration in a room by
> > > a bidirectional airflow through an open window can not be calculated
> so
> > far.
> > >
> > > Currently I am using ESP-r, version 11.3: Does this (or a future ?)
> > > version show the ability to assess indoor air quality in rooms with
> > > natural ventilation (which means BI-DIRECTIONAL air flow must be taken
> > > into account completely) ?
> > >
> > > Best regards,
> > > Gunter
> > >
> > > --
> > > Dr. Gunter Pültz
> > >
> > > Müller-BBM GmbH
> > > Robert-Koch-Straße 11
> > > 82152 Planegg
> > > Telefon +49 (0)89 85602 - 336
> > > Telefax +49 (0)89 85602 - 111
> > > http://www.MuellerBBM.de
> > >
> > > HRB München 86143
> > > Geschäftsführer: Bernd Grözinger, Dr. Edwin Schorer, Norbert Suritsch
> >
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