oThanks for the photos.
I cannot see from the photo what you are doing with PCM material.
The test cell is also not conventional from building simulation.
Special precaution is required to do the simulation on the test, as it is a single zone, isolated from ground. It is not the best to do building research, if the unit is to be used as a residential unit.
I have no idea what you are trying to measure with the test cell. With the EPlus 5 zone model, the solar radiation impacts different part of the building at different time of the day. The peripheral zones facing different directions will have different solar loading.
As the OD temperature changes and the sun position moves, a user can a feel of the heat load on the building without doing four different simulations, for example by moving the window to each surface of your test cell or to rotate your test cell.
When you mentioned that you embedded sensor in the test cell, I thought you were inserting the sensor in the center layer of a wall material. I think, you meant measuring the cell interior temperature, which is the zone mean air temperature.
What you can do is to an annual simulation using the TMY and then record te daily ODT and solar conditions, and then compare the ODT with the TMY ODT near the current date. The order of matching between the TMY and actual data would show how much the measured zone value should be.
It is not an easy task, as the OD temperature is not easily measured without taking special precaution in making the measurements. When I was installing a weather radar at an RAF weather station at Singapore airport (1959), I saw their manual data collecting set up. The thermometer is to be shielded from the radiation and exposed to the convection air current.
In 2007, Mr. Ooi used a 30 channel data logger to collect OD, and surface temperature of a building simultaneously for his PhD research program. The thesis is not available yet.
Infiltration depends on wind direction, etc. Therefore, you should apply with care.
Because the floor is not in contact with the the ground. The simulation floor "ground" condition is also unkown.
The wall reference.idf has two zones. Only one zone was visible in the photo. The blue part may be the test cell, mounted on the partition wall.
These are my observation after viewing the photos.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: mohammadkheradmand@xxxxxxxxx
Date: Wed, 14 Mar 2012 03:28:29 -0700
Subject: Re: [EnergyPlus_Support] define schedule compact for infiltration to reach convergence results
From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Tuesday, March 13, 2012 11:47 PM
Subject: RE: [EnergyPlus_Support] define schedule compact for infiltration to reach convergence results
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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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I cannot see from the photo what you are doing with PCM material.
The test cell is also not conventional from building simulation.
Special precaution is required to do the simulation on the test, as it is a single zone, isolated from ground. It is not the best to do building research, if the unit is to be used as a residential unit.
I have no idea what you are trying to measure with the test cell. With the EPlus 5 zone model, the solar radiation impacts different part of the building at different time of the day. The peripheral zones facing different directions will have different solar loading.
As the OD temperature changes and the sun position moves, a user can a feel of the heat load on the building without doing four different simulations, for example by moving the window to each surface of your test cell or to rotate your test cell.
When you mentioned that you embedded sensor in the test cell, I thought you were inserting the sensor in the center layer of a wall material. I think, you meant measuring the cell interior temperature, which is the zone mean air temperature.
What you can do is to an annual simulation using the TMY and then record te daily ODT and solar conditions, and then compare the ODT with the TMY ODT near the current date. The order of matching between the TMY and actual data would show how much the measured zone value should be.
It is not an easy task, as the OD temperature is not easily measured without taking special precaution in making the measurements. When I was installing a weather radar at an RAF weather station at Singapore airport (1959), I saw their manual data collecting set up. The thermometer is to be shielded from the radiation and exposed to the convection air current.
In 2007, Mr. Ooi used a 30 channel data logger to collect OD, and surface temperature of a building simultaneously for his PhD research program. The thesis is not available yet.
Infiltration depends on wind direction, etc. Therefore, you should apply with care.
Because the floor is not in contact with the the ground. The simulation floor "ground" condition is also unkown.
The wall reference.idf has two zones. Only one zone was visible in the photo. The blue part may be the test cell, mounted on the partition wall.
These are my observation after viewing the photos.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: mohammadkheradmand@xxxxxxxxx
Date: Wed, 14 Mar 2012 03:28:29 -0700
Subject: Re: [EnergyPlus_Support] define schedule compact for infiltration to reach convergence results
Hello Dr. Li,
Thanks again for wide spread information,
In my case,we did experimental tests that in detail:
A test cell which created a wall inside it we put sensors in two parts(north and south ambient part of cell) for measuring temperate changes and i try to simulate it by E+(attached pictures). when i put infiltration such as .idf file i can obtain good results in simulation,but i am not sure that is correct or not ...because infiltration can be exist in real. could you please put comment for me? how can
i evaluate my simulation.
regards
From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Tuesday, March 13, 2012 11:47 PM
Subject: RE: [EnergyPlus_Support] define schedule compact for infiltration to reach convergence results
There is no problem with your IDF, except that you do not have DesignDay sizing.
The air infiltration rates to the zones were very high, 0.5 to 3.5 ACH.
You can add the followings to display them.
============================
Output:Variable,*,Zone Mean Air Temperature,Timestep;
Output:Variable,*,Outdoor dry bulb,Timestep;
Output:Variable,*,Schedule Value,Timestep;
Output:Variable,*,Zone Infiltration Air Change Rate,Timestep;
==============================
Output:Table:TimeBins,
*, !- Key Value
Zone Mean Air Temperature, !- Variable Name
, !- Interval Start
, !- Interval Size
20, !- Interval Count
, !- Schedule Name
Temperature; !- Variable Type
============================
I do not know what this is for and was not simulated.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: mohammadkheradmand@xxxxxxxxx
Date: Tue, 13 Mar 2012 10:31:59 -0700
Subject: [EnergyPlus_Support] define schedule compact for infiltration to reach convergence results
From: saleh saadi <salehsnjsaadi404@xxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Thursday, March 8, 2012 7:33 PM
Subject: Re: [EnergyPlus_Support] what can i do for convergence the result ?
The air infiltration rates to the zones were very high, 0.5 to 3.5 ACH.
You can add the followings to display them.
============================
Output:Variable,*,Zone Mean Air Temperature,Timestep;
Output:Variable,*,Outdoor dry bulb,Timestep;
Output:Variable,*,Schedule Value,Timestep;
Output:Variable,*,Zone Infiltration Air Change Rate,Timestep;
==============================
Output:Table:TimeBins,
*, !- Key Value
Zone Mean Air Temperature, !- Variable Name
, !- Interval Start
, !- Interval Size
20, !- Interval Count
, !- Schedule Name
Temperature; !- Variable Type
============================
I do not know what this is for and was not simulated.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: mohammadkheradmand@xxxxxxxxx
Date: Tue, 13 Mar 2012 10:31:59 -0700
Subject: [EnergyPlus_Support] define schedule compact for infiltration to reach convergence results
Hello,
Could you please explain to me this point in
schedule compact:
Field: Value
Finally, the value field is the schedule value for the specified time interval.
what is meaningful of it? and is it true that i did in .idf file till now?
regards,
From: saleh saadi <salehsnjsaadi404@xxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Thursday, March 8, 2012 7:33 PM
Subject: Re: [EnergyPlus_Support] what can i do for convergence the result ?
Does the simulation underestimate or overestimate your experimental results?
You might need to consider the infiltration in your model. try to use simple convective heat transfer coefficient algorithm.
Use real weather data measured at site.
what is the uncertainty in your measurements equipment. ? your results need to be within 1 deg difference. (3-4) degree difference is large.
regards,
From: Mohammad Kheradmand <mohammadkheradmand@xxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Thursday, March 8, 2012 11:06 AM
Subject: [EnergyPlus_Support] what can i do for convergence the result ?
You might need to consider the infiltration in your model. try to use simple convective heat transfer coefficient algorithm.
Use real weather data measured at site.
what is the uncertainty in your measurements equipment. ? your results need to be within 1 deg difference. (3-4) degree difference is large.
regards,
From: Mohammad Kheradmand <mohammadkheradmand@xxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Thursday, March 8, 2012 11:06 AM
Subject: [EnergyPlus_Support] what can i do for convergence the result ?
I simulate my model for coldest and hottest a day of August, for comparing results between experimental and simulation results, i got reasonable result for hottest day(almost 4-5 degree differences ), but for coldest day i have difference almost 10-12 degree ...what is my problem?
regards
__._,_.___
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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