Re: [EnergyPlus_Support] DSF

[Lixing Gu <gu@xxxxxxxxxxxx>]

1    DSF model

When the AirflowNetwork model is used, airflow rates can be calculated due 
to pressure differences. However, cavity convection is not simulated 
correctly. The airflows calculated using the model are a part of zone energy 
balance only. Therefore, the model is not correct to simulate DSF. I am not 
sure which window model is used for the other approach.

2    Mass balance

Mass conservation is based on a zone (all incoming flows = all outgoing 
flows), not a component. Please look at the Pressure and Airflow 
Calculations section of Engineering Reference on page 379.

Best regards,

Lixing Gu
Florida Solar Energy Center
1679 Clearlake Road
Cocoa, FL 32922
Phone: (321) 638-1411
Fax: (321) 638-1439

----- Original Message ----- 
From: "creamy_1023" <creamy_1023@xxxxxxxxxxxx>
To: <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Monday, July 28, 2008 8:04 AM
Subject: [EnergyPlus_Support] DSF


>I have two questions about double skin facade model.
>
> 1. I input the DSF as a separate zone. In a DSF, there should have two
> opening to let the air flow in and out. I had input the opening as two
> methods. The first one is add two windows in Heat transfer surface:sub
> on the surface of DSF. The second one is add two opening in Airflow
> Network: Detailed Opening Component on the surface of DSF. But they
> have two different results of volume flow rate. Which one is correct??
>
> 2. Also, the airflow rate from node 1 to node 2 (inside to outside) in
> DSF should be equal to the airflow rate from node 2 to node 1 (Outside
> to inside), because of the conservation of mass. However, they are not
> equal. It's there any reasons??
>
> Thanks!
>
>
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