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if i want to simulated a naturally ventilated trombe wall in energyplus then which object i have to specify for the airflow network between trombe cavity and receiving zone in energyplus?

asked 2019-04-21 22:45:22 -0500

muin gravatar image

updated 2019-04-22 07:49:51 -0500

i want to simulate a naturally ventilated trombe wall for zone heating using e+. but i do not know the proper object from e+ to ensure proper air flow from trombe (Source Zone) cavity to the receiving zone. i need expert opinion in this regards.

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answered 2019-04-29 17:18:25 -0500

updated 2019-05-09 10:39:47 -0500

I haven't tried this myself, so it may be possible to do this with AirflowNetwork. However, it may be difficult to get the network to behave as desired without basically overspecifying the problem (i.e. setting the flow rates), in which case the pressure network is overkill. I doubt that the solution will involve AirflowNetwork:Distribution:Linkage since that is used for distribution systems. How complicated is the building, and have you experimented with the example files that implement Trombe walls? Depending on what you're trying to do, this might work out just as well.

The minimal AirflowNetwork that might be able to get you something like you want is to use two surfaces, one high and one low, to represent the partition between the Trombe zone and the interior zone. Simplest thing to do would be to divide the partition in two, which won't quite have the heights right (the airflow calculation uses the elevation of the center of the surface), but it's a place to start. Create a AirflowNetwork:Multizone:Zone for both of your zones, attach a AirflowNetwork:Multizone:Surface to both the high and the low surface, and then attach a leakage component. You probably need to connect to the ambient to get a good solution, you can do that with a high resistance component connecting the interior zone to the outside.

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@Jason DeGraw thanks for your answer. i have tried the example file of passive trombe wall which is for a sealed or unvented Trombe wall, but in my trombe wall there is two vent in upper and lower part of trombe wall. and i am trying same building geometry as like example file adding two vent in trombe wall.

muin gravatar image muin  ( 2019-05-05 01:35:00 -0500 )edit

@muin In that case, I'll update my answer to give some more information

Jason DeGraw gravatar image Jason DeGraw  ( 2019-05-08 12:29:32 -0500 )edit

I have the same problem working with passive solar solution. I am trying to simulate a convective loop, that is, a sort of ventilated Trombe wall with low thermal storage, and I also would like to simulate a use as a solar chimney during summer. Now I am trying to get a early stage result with a Zone Mixing, setting a schedule via EMS to get a flow rate based on DT between the two zone when outdoor temperature is higher then indoor set point, and toward outdoor environment when is lower. I know is a weak model, but I don't know how to implement a proper complex airflow network

Giacomo90 gravatar image Giacomo90  ( 2020-07-16 15:23:16 -0500 )edit
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answered 2019-04-29 12:50:26 -0500

See the documentation for the AirflowNetwork:Distribution:Linkage object. The following output variables will give you mass/volume flow rates between nodes in an airflow network:

HVAC,Average,AFN Linkage Node 1 to Node 2 Mass Flow Rate [kg/s]
HVAC,Average,AFN Linkage Node 2 to Node 1 Mass Flow Rate [kg/s]
HVAC,Average,AFN Linkage Node 1 to Node 2 Volume Flow Rate [m3/s]
HVAC,Average,AFN Linkage Node 2 to Node 1 Volume Flow Rate [m3/s]
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@ericmartinpe thanks for your answer. may be AirflowNetwork:Distribution:Linkage object is suitable for conditioned space but i am considering here an unconditioned zone.

muin gravatar image muin  ( 2019-05-05 01:21:54 -0500 )edit

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Asked: 2019-04-21 22:40:19 -0500

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Last updated: May 09 '19