What you are doing is very similar to what Mr. Ooi KB was doing in his project.
He found that the an air speed over the human skin provides comfortable cool feeling and can raised the temperature limits set by ASHRAE.
If you have a room with two windows, the velocity x window area (one only, in at one and out the other) is the air volume flowing through.
Infiltration object does not use energy, but may require external wind velocity. Ventilation object has a fan to force the air through.
AirflowNetwork3zVent.idf
AirflowNetwork_MultiZone_House.idf
AirflowNetwork_Simple_House.idf
I am not sure which of the above I looked at two years ago. Probably the multi-zone one, as I recall it has a window to one room, a door between rooms and a window in the second room. The air flow passes the building with wind coming from different directions and at different speed. There are also cracks on the walls.
I have not tried to add any heating or cooling to it.
I did not go more work on that because I found that the use of external shading is more efficient.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: zqianmin@xxxxxxxxx
Date: Thu, 21 Jul 2011 16:17:13 -0700
Subject: Re: [EnergyPlus_Support] Natural Ventilation
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Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
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He found that the an air speed over the human skin provides comfortable cool feeling and can raised the temperature limits set by ASHRAE.
If you have a room with two windows, the velocity x window area (one only, in at one and out the other) is the air volume flowing through.
Infiltration object does not use energy, but may require external wind velocity. Ventilation object has a fan to force the air through.
AirflowNetwork3zVent.idf
AirflowNetwork_MultiZone_House.idf
AirflowNetwork_Simple_House.idf
I am not sure which of the above I looked at two years ago. Probably the multi-zone one, as I recall it has a window to one room, a door between rooms and a window in the second room. The air flow passes the building with wind coming from different directions and at different speed. There are also cracks on the walls.
I have not tried to add any heating or cooling to it.
I did not go more work on that because I found that the use of external shading is more efficient.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: zqianmin@xxxxxxxxx
Date: Thu, 21 Jul 2011 16:17:13 -0700
Subject: Re: [EnergyPlus_Support] Natural Ventilation
The air path is not important for this project. But, they don't have any design of air flow as far as I know. I can put a mechanical fan in system and set its power to zero, if I can find the ACH based on their occupancy schedule.
This project has a certain capacity of thermal tank to store chilled water from night sky cooling roof to provide the cooling capacity. They accept the uncomfortable condition if the sensible cooling capacity is not big enough. I feel difficult to model the natural ventilation plus radiant system, their control logical.
Which example file should I look at to know the minimum input for using AFN? Or I approximate the ACH based on its occupancy schedule? Thanks a lot.
Regards,
Qianmin
On Thu, Jul 21, 2011 at 10:52 AM, YuanLu Li <yli006@xxxxxxxxxxx> wrote:
Not easy. AFN will give you many details.
However, I only look for the zone temperature with ventilation object.
Use external shades and internal heat control (vent the heat sources out directly.)
The main difference with and without AFN is the exact location of the air flowing in and out of the building and the air flow path. They are dependent on the outside wind condition.
If the ACH rate is about the same as with the AFN simulation, the room temperature below 28°C may be considered as comfortable simulated using EPlus with the windows closed and with ventilation object to feed the outside air into the building. Mr. Ooi, KB may be able to add to this.
In the actual buiding, the windows and louvers would be open to provide a similar ACH rate or moving air in the room with a fan.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: zqianmin@xxxxxxxxx
Date: Thu, 21 Jul 2011 10:40:29 -0700
Subject: [EnergyPlus_Support] Natural Ventilation
Hello, I have question about natural ventilation.How to model natural ventilation in energyplus? Do I need to define like window opening schedule or any precalculation? There is no auto control for these window, and what I have are window material, size, and radiant system design. For local condition, dry hot summer temperature, natural ventilation take care of the latent load firstly, even it will increase zone sensible load, and the radiant cooling will take care the sensible load. No mechanical fan at all.I saw the object of AirFlowNetwork, but haven't try it yet. I would appreciate your opinion. Thanks.Qianmin
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
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 currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
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