I am not really interested in LEED certification or number of Green Stars for building.
The 'green' toilet approved by the government 'green' grant is terrible. They are there to sell houses and get government grants. A window cannot be open for more than three inch wide according to the City high rise by-law. Install air-conditioning units, but may not be used when the electricity power is on brown out. There are lots to be done, if we really wanted to conserve energy.
I do not bare my skin and go into the sun with sun tan lotion on a hot day. I do not own any short sleeve shirts, even when I was in Singapore. Natural ventilation by sweat infiltration to material also applies to clothings.
AFN with full air distribution simullation is very useful for building services design.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: jeannieboef@xxxxxxxxx
Date: Fri, 22 Jul 2011 04:52:33 +0000
Subject: [EnergyPlus_Support] Re: 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:
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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The 'green' toilet approved by the government 'green' grant is terrible. They are there to sell houses and get government grants. A window cannot be open for more than three inch wide according to the City high rise by-law. Install air-conditioning units, but may not be used when the electricity power is on brown out. There are lots to be done, if we really wanted to conserve energy.
I do not bare my skin and go into the sun with sun tan lotion on a hot day. I do not own any short sleeve shirts, even when I was in Singapore. Natural ventilation by sweat infiltration to material also applies to clothings.
AFN with full air distribution simullation is very useful for building services design.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: jeannieboef@xxxxxxxxx
Date: Fri, 22 Jul 2011 04:52:33 +0000
Subject: [EnergyPlus_Support] Re: Natural Ventilation
Agreed. Infiltration Ventilation objects also account for wind and temperature differences to vary the design flow rate. The problem is estimating or calculating the design flow rate.AFN does not require so much guess work, but also has limitations. Large openings and horizontal openings are unsurely modelled (if you read some of the old Contam and AFN papers you will understand why). You'll need to input some crack coeff. data which needs some "guessing", but luckily the errors resulting are small. AFN is the most accurate, but you can get lost in its complexity. For complex models some softwares like Design Builder can automatically generate you the network. But the downside is you will have a crack on every surface. That's often only interisting on the envelope, and the massive size of the network slows computation.
In building practice it is acceptable to estimate calculate a design infiltration rate. If you use two models to compare properties, you will still be comparing apples with apples.
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> 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@...
> Date: Thu, 21 Jul 2011 10:40:29 -0700
> Subject: [EnergyPlus_Support] Natural Ventilation
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> 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.
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> I saw the object of AirFlowNetwork, but haven't try it yet. I would appreciate your opinion. Thanks.
> Qianmin
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In building practice it is acceptable to estimate calculate a design infiltration rate. If you use two models to compare properties, you will still be comparing apples with apples.
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> 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@...
> Date: Thu, 21 Jul 2011 10:40:29 -0700
> Subject: [EnergyPlus_Support] Natural Ventilation
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> 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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