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Is it possible to model an airloop with zones in series instead of in parallel in E+ - Revised

asked 2015-11-17 08:04:42 -0500

updated 2016-03-23 16:41:08 -0500

I'm trying to model a mechanical ventilation system with heat recuperation in a two zone model.

The zones are connected in series (supply fan, zone splitter, air inlet in zone1, mixing object between zone1 and zone2, return node from zone2, zone mixer, extract fan.

The simulation runs without errors, but in the svg file I only see zone1, while i would like to see zone 2 connected in series.

Do I have to model the system in parallel and set the supply flow rate of zone2 and the return flow rate of zone1 to zero or is there an alternative? (is mixing visualized in the svg file?)


Do I need a fictional exhaust fan in the system that I described above if I use zone mixing and put "Zone Air Mass Flow Conservation" to on (= to "yes")?

Actually the system looks exactly like this without the m'R1 and m'S2:

image description

According to some other posts it is necessary, but when I do it the mass flow output from the exhaust fan seems to be 0 at every timestep. The flows are balanced:

Supply air mass flow rate in zone 1

= mixing source air mass flow rate in zone 1

= mixing receiving air mass flow rate in zone 2

= return air mass flow rate in zone 2.

I have the impression that I am missing something...

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I think you should also try to output nodes temperatures and flow rates to find out what is happening in the system, don't just rely on the svg figure.

Waseem gravatar image Waseem  ( 2015-11-17 08:18:04 -0500 )edit

I agree (and I am doing that) but it doesn't change my question.

BBel gravatar image BBel  ( 2015-11-17 09:00:56 -0500 )edit

Please use existing tags separated by spaces. Thanks.

__AmirRoth__ gravatar image __AmirRoth__  ( 2015-11-17 10:23:17 -0500 )edit

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answered 2015-11-17 09:06:57 -0500

If your system is ventilation only, with no return flow to the AirLoop, then you can define a ZoneMixing object to define flow from the supplying zone to the exhausting zone. Note that with this method, you'll want to define a fictional exhaust fan in the supplying zone, since the ZoneMixing object will 'credit' the mixing air volume to the receiving zone without subtracting from the supply zone. Thus the fictional exhaust fan is used to maintain the correct air balance in the supplying zone.

If you are recirculating zone air back to the AirLoop, you can define one of the zones as a supply or return plenum to have two zones in series in the air path.

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Hi Eric,

At the moment my mixing object doesn't work. I don't get air any airflow in the receiving zone.

The air that is supplied to zone 1 is returned by the return node of zone 1 instead of the return node of zone 2. (can I turn off a zone return node?)

In zone 2 there is no flow although a mixing object between zone 1 and 2 is available and ZoneAirMassflowConservation is on.

Any ideas?

BBel gravatar image BBel  ( 2015-11-26 07:13:48 -0500 )edit

You can discard my comment, but I will keep it for further information. The reason zone mixing wasn't working was that I had an active airflow network in my model, so zone mixing was overruled.

BBel gravatar image BBel  ( 2015-11-26 09:28:58 -0500 )edit

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Asked: 2015-11-17 08:04:42 -0500

Seen: 351 times

Last updated: Mar 23 '16