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Issue with SurfaceControl:MovableInsulation for wall applications
I've been working on dynamic insulation systems and successfully used the EMS surface construction actuator. Now, I'm looking to explore the surface control movable insulation object in EnergyPlus. However, I'm encountering some discrepancies in my results that I can't quite understand.
I reviewed the documentation and examined the two example files that use interior and exterior movable insulation to understand how it’s modeled. Below is a summary of the tests I've conducted using the example file “MovableExtInsulationSimple.idf”of version 9.6, focusing on one wall. I expected the energy use to be similar for all matching colors since the same construction materials were applied.

Additionally, I ran the tests for all walls to assess the overall impact.

Here is what I noticed:
The results are identical when modeling the movable insulation as exterior, interior, or a combination of both with an always OFF schedule compared to modeling the insulation layer as part of the construction class list, which is great!
The discrepancy in the results is relatively small when comparing outside movable insulation with an always ON schedule to modeling the exterior insulation layer as part of the construction class list.
The results are significantly different when using inside movable insulation. Why is this not similar to modeling the interior insulation as part of the construction class list??
I am aware that there was some logic refactoring for the movable insulation module in version 9.6, but could this still be a bug? Any insights or suggestions would be greatly appreciated, thanks!
Issue with SurfaceControl:MovableInsulation for wall applications
I've been working on dynamic insulation systems and successfully used the EMS surface construction actuator. Now, I'm looking to explore the surface control movable insulation object in EnergyPlus. However, I'm encountering some discrepancies in my results that I can't quite understand.
I reviewed the documentation and examined the two example files that use interior and exterior movable insulation to understand how it’s modeled. Below is a summary of the tests I've conducted using the example file “MovableExtInsulationSimple.idf”of version 9.6, focusing on one wall. I expected the energy use to be similar for all matching colors since the same construction materials were applied.

Additionally, I ran the tests for all walls to assess the overall impact.

Here is what I noticed:
The results are identical when modeling
the movable insulation asexterior, interior, or a combination of both with an always OFF schedule compared to modeling the insulation layer as part of the construction class list, which is great!The discrepancy
in the resultsis relatively small when comparing outside movable insulation with an always ON schedule to modeling the exterior insulation layer as part of the construction class list.The results are significantly different when using inside movable insulation. Why is this not similar to modeling the interior
insulationwall as part of the construction class list??
I am aware that there was some logic refactoring for the movable insulation module in version 9.6, but could this still be a bug? Any insights or suggestions would be greatly appreciated, thanks!
Issue with SurfaceControl:MovableInsulation for wall applications
I've been working on dynamic insulation systems and successfully used the EMS surface construction actuator. Now, I'm looking to explore the surface control movable insulation object in EnergyPlus. However, I'm encountering some discrepancies in my results that I can't quite understand.
I reviewed the documentation and examined the two example files that use interior and exterior movable insulation to understand how it’s modeled. Below is a summary of the tests I've conducted using the example file “MovableExtInsulationSimple.idf”of version 9.6, focusing on one wall. I expected the energy use to be similar for all matching colors since the same construction materials were applied.

Additionally, I ran the tests for all walls to assess the overall impact.

Here is what I noticed:
The results are identical when modeling exterior, interior, or a combination of both with an always OFF schedule compared to modeling the insulation layer as part of the construction class list, which is great!
The discrepancy is relatively small when comparing outside movable insulation with an always ON schedule to modeling the exterior insulation layer as part of the construction class list.
The results are significantly different when using inside movable insulation. Why is this not similar to modeling the interior wall as part of the construction class list??
I am aware that there was some logic refactoring for the movable insulation module in version 9.6, but could this still be a bug? Any insights or suggestions would be greatly appreciated, thanks!
Issue with SurfaceControl:MovableInsulation for wall roof applications
I've been working on dynamic insulation systems and successfully used the EMS surface construction actuator. Now, I'm looking to explore the surface control movable insulation object SurfaceControl
object in EnergyPlus. However, I'm encountering some discrepancies in my results that I can't quite understand.
I reviewed the documentation and examined the two example files that use interior and exterior movable insulation to understand how it’s modeled. Below is a summary of the tests I've conducted using the example file “MovableExtInsulationSimple.idf”of version 9.6, focusing on one wall. I expected the energy use to be similar for all matching colors since the same construction materials were applied.
C:\fakepath\unmethours_pcm_1wall.png
Additionally, I ran the tests for all walls to assess the overall impact.
C:\fakepath\unmethours_pcm_allwall.png
Here is what I noticed:
The results are identical when modeling exterior, interior, or a combination of both with an always OFF schedule compared to modeling the insulation layer as part of the construction class list, which is great!
The discrepancy is relatively small when comparing outside movable insulation with an always ON schedule to modeling the exterior insulation layer as part of the construction class list.
The results are significantly different when using inside movable insulation. Why is this not similar to modeling the interior wall as part of the construction class list??
I am aware that there was some logic refactoring for the movable insulation module in version 9.6, but could this still be a bug? Any insights or suggestions would be greatly appreciated, thanks!
Issue with SurfaceControl:MovableInsulation for roof applications
I've been working on dynamic insulation systems and successfully used the EMS surface construction actuator. Now, I'm looking to explore the SurfaceControl object in EnergyPlus. However, I'm encountering some discrepancies in my results that I can't quite understand.
I reviewed the documentation and examined the two example files that use interior and exterior movable insulation to understand how it’s modeled. Below is a summary of the tests I've conducted using the example file “MovableExtInsulationSimple.idf”of version 9.6, focusing on one wall. I expected the energy use to be similar for all matching colors since the same construction materials were applied.
C:\fakepath\unmethours_pcm_1wall.png
Additionally, I ran the tests for all walls to assess the overall impact.
C:\fakepath\unmethours_pcm_allwall.png
Here is what I noticed:
The results are identical when modeling exterior, interior, or a combination of both with an always OFF schedule compared to modeling the insulation layer as part of the construction class list, which is great!
The discrepancy is relatively small when comparing outside movable insulation with an always ON schedule to modeling the exterior insulation layer as part of the construction class list.
The results are significantly different when using inside movable insulation. Why is this not similar to modeling the interior wall as part of the construction class list??
I am aware that there was some logic refactoring for the movable insulation module in version 9.6, but could this still be a bug? Any insights or suggestions would be greatly appreciated, thanks!
Issue with SurfaceControl:MovableInsulation for roof applications
I've I have been working on dynamic insulation systems and successfully used the EMS I was able to use the surface construction actuator. actuator within EMS. Now, I'm looking I would like to explore the SurfaceControl
SurfaceControl:MovableInsulation object in EnergyPlus. However, I'm encountering within energyplus but I am struggling to understand some of the discrepancies in my results that I can't quite understand.
I reviewed that I am getting! I checked the documentation and examined the two example files that use interior and exterior movable insulation to understand check how it’s it is modeled. Below is The table below shows a summary of the tests I've conducted I have been running using the example file “MovableExtInsulationSimple.idf”of version 9.6, focusing on one wall. "Material:NoMass" class and CondFD algorithm with a 3 min timestep. I expected the that all the matching colors would have similar energy use to be similar for all matching colors since I am using the same construction materials were applied.

1- I notice a big difference between the results when I add the insulation material as part of the construction compared to when I have it in the movable insulation object which is similar to the issue described in SurfaceControl: Movable Insulation vs Construction Properties @ EnergyPlus
Additionally, I ran the tests . This difference appears to be significant when I consider inside movable insulation (Rows highlighted in yellow) and less significant when I consider outside movable insulation (Rows highlighted in green) as shown in the table. I tried adding the material using both "Material" and "Material:NoMass" classes but the issue still persists.
2- If I consider inside movable insulation, then the results are completely off. It seems there is an issue with the heat balance for the movable insulation. I am reporting the node temperatures in addition to the inside and outside surface temperatures of the roof. When I check these results, I get some temperature values for inside and outside surface temps but for all walls to assess the overall impact.
C:\fakepath\unmethours_pcm_allwall.pngthe roof nodes (including node 1 and last node) the temperatures are always 23 C which I think is the initial temperature. Do you think this issue is related to the materials I am using as part of the roof construction that could influence the heat balance? could it be related to the heat balance algorithm (i.e. CTF vs CondFD) as I can see that everything is related to CTF in the C++ code in Surface Heat Balances With Moveable Insulation
Here is what I noticed:
The . Also could it be related to the surface convection algorithm (inside/outside)? I am using TARP for inside and Adaptive for outside.
3- You can notice that when I use inside movable insulation (#7) with a schedule of 0 (OFF), this results
are identical when modeling exterior, interior,in exactly the same energy use as when the construction has no insulation (#1), however, this is different when using outside movable insulation with a schedule of 0 (#4).Theses cases were simulated using the CondFD algorithm as I eventually want to include PCM as part of the construction. However, I tried the tests without including a PCM layer and considering CondFD as well as CTF but both showed similar patterns except that CTF results in a large heating energy use (39,267 kWh) compared to the small figure (66 kWh) from CondFD when the inside movable insulation is considered.
I found some articles that used the SurfaceControl:MovableInsulation approach when the insulation is located inside and outside of a wall assembly link. So I am thinking maybe I am missing something or
a combination of both with an always OFF schedule compared to modeling the insulation layer as part of the construction class list, which is great!The discrepancy is relatively small when comparing outside movable insulation with an always ON schedule to modeling the exterior insulation layer as part of the construction class list.
The results are significantly different when using inside movable insulation. Why is this not similar to modeling the interior wall as part of the construction class list??
I am aware that there was some logic refactoring for the movable insulation module in version 9.6, doing something wrong! .
I tried to make it short but could this still be a bug? I hope it is clear. Any insights thoughts or suggestions would be greatly appreciated, helpful, thanks!
Issue with SurfaceControl:MovableInsulation for roof applications
I have been working on dynamic insulation systems and I was able to use the surface construction actuator within EMS. Now, I would like to explore the SurfaceControl:MovableInsulation object within energyplus but I am struggling to understand some of the discrepancies that I am getting! I checked the documentation and the two example files that use interior and exterior movable insulation to check how it is modeled. The table below shows a summary of the tests I have been running using the "Material:NoMass" class and CondFD algorithm with a 3 min timestep. I expected that all the matching colors would have similar energy use since I am using the same construction materials but surprisingly they are not the same! some of them are not even close!

1- I notice a big difference between the results when I add the insulation material as part of the construction compared to when I have it in the movable insulation object which is similar to the issue described in SurfaceControl: Movable Insulation vs Construction Properties @ EnergyPlus. This difference appears to be significant when I consider inside movable insulation (Rows highlighted in yellow) and less significant when I consider outside movable insulation (Rows highlighted in green) as shown in the table. I tried adding the material using both "Material" and "Material:NoMass" classes but the issue still persists.
2- If I consider inside movable insulation, then the results are completely off. It seems there is an issue with the heat balance for the movable insulation. I am reporting the node temperatures in addition to the inside and outside surface temperatures of the roof. When I check these results, I get some temperature values for inside and outside surface temps but for all the roof nodes (including node 1 and last node) the temperatures are always 23 C which I think is the initial temperature. Do you think this issue is related to the materials I am using as part of the roof construction that could influence the heat balance? could it be related to the heat balance algorithm (i.e. CTF vs CondFD) as I can see that everything is related to CTF in the C++ code in Surface Heat Balances With Moveable Insulation. Also could it be related to the surface convection algorithm (inside/outside)? I am using TARP for inside and Adaptive for outside.
3- You can notice that when I use inside movable insulation (#7) with a schedule of 0 (OFF), this results in exactly the same energy use as when the construction has no insulation (#1), however, this is different when using outside movable insulation with a schedule of 0 (#4).
Theses cases were simulated using the CondFD algorithm as I eventually want to include PCM as part of the construction. However, I tried the tests without including a PCM layer and considering CondFD as well as CTF but both showed similar patterns except that CTF results in a large heating energy use (39,267 kWh) compared to the small figure (66 kWh) from CondFD when the inside movable insulation is considered.
I found some articles that used the SurfaceControl:MovableInsulation approach when the insulation is located inside and outside of a wall assembly link. So I am thinking maybe I am missing something or doing something wrong! .
I tried to make it short but I hope it is clear. Any thoughts or suggestions would be helpful, thanks!
Issue with SurfaceControl:MovableInsulation for roof applications
Hello everyone,
I have been working on dynamic insulation systems and I was able to use the surface construction actuator within EMS. Now, I would like to explore the SurfaceControl:MovableInsulation object within energyplus but I am struggling to understand some of the discrepancies that I am getting! I checked the documentation and the two example files that use interior and exterior movable insulation to check how it is modeled. The table below shows a summary of the tests I have been running using the "Material:NoMass" class and CondFD algorithm with a 3 min timestep. I expected that all the matching colors would have similar energy use since I am using the same construction materials but surprisingly they are not the same! some of them are not even close!

1- I notice a big difference between the results when I add the insulation material as part of the construction compared to when I have it in the movable insulation object which is similar to the issue described in SurfaceControl: Movable Insulation vs Construction Properties @ EnergyPlus. This difference appears to be significant when I consider inside movable insulation (Rows highlighted in yellow) and less significant when I consider outside movable insulation (Rows highlighted in green) as shown in the table. I tried adding the material using both "Material" and "Material:NoMass" classes but the issue still persists.
2- If I consider inside movable insulation, then the results are completely off. It seems there is an issue with the heat balance for the movable insulation. I am reporting the node temperatures in addition to the inside and outside surface temperatures of the roof. When I check these results, I get some temperature values for inside and outside surface temps but for all the roof nodes (including node 1 and last node) the temperatures are always 23 C which I think is the initial temperature. Do you think this issue is related to the materials I am using as part of the roof construction that could influence the heat balance? could it be related to the heat balance algorithm (i.e. CTF vs CondFD) as I can see that everything is related to CTF in the C++ code in Surface Heat Balances With Moveable Insulation. Also could it be related to the surface convection algorithm (inside/outside)? I am using TARP for inside and Adaptive for outside.
3- You can notice that when I use inside movable insulation (#7) with a schedule of 0 (OFF), this results in exactly the same energy use as when the construction has no insulation (#1), however, this is different when using outside movable insulation with a schedule of 0 (#4).
Theses cases were simulated using the CondFD algorithm as I eventually want to include PCM as part of the construction. However, I tried the tests without including a PCM layer and considering CondFD as well as CTF but both showed similar patterns except that CTF results in a large heating energy use (39,267 kWh) compared to the small figure (66 kWh) from CondFD when the inside movable insulation is considered.
I found some articles that used the SurfaceControl:MovableInsulation approach when the insulation is located inside and outside of a wall assembly link. So I am thinking maybe I am missing something or doing something wrong! .
I tried to make it short but I hope it is clear. Any thoughts or suggestions would be helpful, thanks!
Ammar
Issue with SurfaceControl:MovableInsulation for roof applications
Hello everyone,
I have been working on dynamic insulation systems and I was able to use the surface construction actuator within EMS. Now, I would like to explore the SurfaceControl:MovableInsulation SurfaceControl:MovableInsulation object within energyplus but I am struggling to understand some of the discrepancies that I am getting! I checked the documentation and the two example files that use interior and exterior movable insulation to check how it is modeled. The table below shows a summary of the tests I have been running using the "Material:NoMass" class and CondFD algorithm with a 3 min timestep. I expected that all the matching colors would have similar energy use since I am using the same construction materials but surprisingly they are not the same! some of them are not even close!

1- I notice a big difference between the results when I add the insulation material as part of the construction compared to when I have it in the movable insulation object which is similar to the issue described in SurfaceControl: Movable Insulation vs Construction Properties @ EnergyPlus. This difference appears to be significant when I consider inside movable insulation (Rows highlighted in yellow) and less significant when I consider outside movable insulation (Rows highlighted in green) as shown in the table. I tried adding the material using both "Material" and "Material:NoMass" classes but the issue still persists.
2- If I consider inside movable insulation, then the results are completely off. It seems there is an issue with the heat balance for the movable insulation. I am reporting the node temperatures in addition to the inside and outside surface temperatures of the roof. When I check these results, I get some temperature values for inside and outside surface temps but for all the roof nodes (including node 1 and last node) the temperatures are always 23 C which I think is the initial temperature. Do you think this issue is related to the materials I am using as part of the roof construction that could influence the heat balance? could it be related to the heat balance algorithm (i.e. CTF vs CondFD) as I can see that everything is related to CTF in the C++ code in Surface Heat Balances With Moveable Insulation. Also could it be related to the surface convection algorithm (inside/outside)? I am using TARP for inside and Adaptive for outside.
3- You can notice that when I use inside movable insulation (#7) with a schedule of 0 (OFF), this results in exactly the same energy use as when the construction has no insulation (#1), however, this is different when using outside movable insulation with a schedule of 0 (#4).
Theses cases were simulated using the CondFD algorithm as I eventually want to include PCM as part of the construction. However, I tried the tests without including a PCM layer and considering CondFD as well as CTF but both showed similar patterns except that CTF results in a large heating energy use (39,267 kWh) compared to the small figure (66 kWh) from CondFD when the inside movable insulation is considered.
I found some articles that used the SurfaceControl:MovableInsulation approach when the insulation is located inside and outside of a wall assembly link. So I am thinking maybe I am missing something or doing something wrong! .
I tried to make it short but I hope it is clear. Any thoughts or suggestions would be helpful, thanks!
Ammar
Issue with SurfaceControl:MovableInsulation for roof applications
Hello everyone,
I have been working on dynamic insulation systems and I was able to use the surface construction actuator within EMS. Now, I would like to explore the SurfaceControl:MovableInsulation object within energyplus but I am struggling to understand some of the discrepancies that I am getting! I checked the documentation and the two example files that use interior and exterior movable insulation to check how it is modeled. The table below shows a summary of the tests I have been running using the "Material:NoMass" class and CondFD algorithm with a 3 min timestep. I expected that all the matching colors would have similar energy use since I am using the same construction materials but surprisingly they are not the same! some of them are not even close!

1- I notice a big difference between the results when I add the insulation material as part of the construction compared to when I have it in the movable insulation object which is similar to the issue described in SurfaceControl: Movable Insulation vs Construction Properties @ EnergyPlus. This difference appears to be significant when I consider inside movable insulation (Rows highlighted in yellow) and less significant when I consider outside movable insulation (Rows highlighted in green) as shown in the table. I tried adding the material using both "Material" and "Material:NoMass" classes but the issue still persists.
2- If I consider inside movable insulation, then the results are completely off. It seems there is an issue with the heat balance for the movable insulation. I am reporting the node temperatures in addition to the inside and outside surface temperatures of the roof. When I check these results, I get some temperature values for inside and outside surface temps but for all the roof nodes (including node 1 and last node) the temperatures are always 23 C which I think is the initial temperature. Do you think this issue is related to the materials I am using as part of the roof construction that could influence the heat balance? could it be related to the heat balance algorithm (i.e. CTF vs CondFD) as I can see that everything is related to CTF in the C++ code in Surface Heat Balances With Moveable Insulation. Also could it be related to the surface convection algorithm (inside/outside)? I am using TARP for inside and Adaptive for outside.
3- You can notice that when I use inside movable insulation (#7) with a schedule of 0 (OFF), this results in exactly the same energy use as when the construction has no insulation (#1), however, this is different when using outside movable insulation with a schedule of 0 (#4).
Theses cases were simulated using the CondFD algorithm as I eventually want to include PCM as part of the construction. However, I tried the tests without including a PCM layer and considering CondFD as well as CTF but both showed similar patterns except that CTF results in a large heating energy use (39,267 kWh) compared to the small figure (66 kWh) from CondFD when the inside movable insulation is considered.
I found some articles that used the SurfaceControl:MovableInsulation approach when the insulation is located inside and outside of a wall assembly link. So I am thinking maybe I am missing something or doing something wrong! .
I tried to make it short but I hope it is clear. Any thoughts or suggestions would be helpful, thanks!
Ammar
Issue with SurfaceControl:MovableInsulation SurfaceControl:Movable Insulation for roof applicationsroof
Hello everyone,
I have been working on dynamic insulation systems and I was able to use the surface construction actuator within EMS. Now, I would like to explore the SurfaceControl:MovableInsulation object within energyplus but I am struggling to understand some of the discrepancies that I am getting! I checked the documentation and the two example files that use interior and exterior movable insulation to check how it is modeled. The table below shows a summary of the tests I have been running using the "Material:NoMass" class and CondFD algorithm with a 3 min timestep. I expected that all the matching colors would have similar energy use since I am using the same construction materials but surprisingly they are not the same! some of them are not even close!

1- I notice a big difference between the results when I add the insulation material as part of the construction compared to when I have it in the movable insulation object which is similar to the issue described in SurfaceControl: Movable Insulation vs Construction Properties @ EnergyPlus.
[here].(https://unmethours.com/question/18475/surfacecontrol-movable-insulation-vs-construction-properties-energyplus/)
This difference appears to be significant when I consider inside movable insulation (Rows highlighted in yellow) and less significant when I consider outside movable insulation (Rows highlighted in green) as shown in the table.
I tried adding the material using both "Material" and "Material:NoMass" classes but the issue still persists.
2- If I consider inside movable insulation, then the results are completely off. It seems there is an issue with the heat balance for the movable insulation. I am reporting the node temperatures in addition to the inside and outside surface temperatures of the roof. When I check these results, I get some temperature values for inside and outside surface temps but for all the roof nodes (including node 1 and last node) the temperatures are always 23 C which I think is the initial temperature. Do you think this issue is related to the materials I am using as part of the roof construction that could influence the heat balance? could it be related to the heat balance algorithm (i.e. CTF vs CondFD) as I can see that everything is related to CTF in the C++ code in this link Surface Heat Balances With Moveable Insulationlink text. Also could it be related to the surface convection algorithm (inside/outside)? I am using TARP for inside and Adaptive for outside.
3- You can notice that when I use inside movable insulation (#7) with a schedule of 0 (OFF), this results in exactly the same energy use as when the construction has no insulation (#1), however, this is different when using outside movable insulation with a schedule of 0 (#4).
Theses cases were simulated using the CondFD algorithm as I eventually want to include PCM as part of the construction. However, I tried the tests without including a PCM layer and considering CondFD as well as CTF but both showed similar patterns except that CTF results in a large heating energy use (39,267 kWh) compared to the small figure (66 kWh) from CondFD when the inside movable insulation is considered.
I found some articles that used the SurfaceControl:MovableInsulation approach when the insulation is located inside and outside of a wall assembly link. So so I am thinking maybe I am missing something or doing something wrong! link text.
I tried to make it short but I hope it is clear. Any thoughts or suggestions would be helpful, thanks!
Ammar
Issue with SurfaceControl:Movable Insulation for roofModeling rooftop BIPV
Hello everyone,
I have been working on dynamic insulation systems and I was able to use the surface construction actuator within EMS. Now, I would like to explore the SurfaceControl:MovableInsulation object within energyplus but I am struggling to understand some of the discrepancies that I am getting! I checked the documentation and the two example files that use interior and exterior movable insulation to check how it is modeled. The table below shows a summary of the tests I have been running using the "Material:NoMass" class and CondFD algorithm with a 3 min timestep. I expected that all the matching colors would have similar energy use since I am using the same construction materials but surprisingly they are not the same! some of them are not even close!

1- I notice a big difference between the results when I add the insulation material as part of the construction compared to when I have it in the movable insulation object which is similar to the issue described [here].(https://unmethours.com/question/18475/surfacecontrol-movable-insulation-vs-construction-properties-energyplus/) This difference appears to be significant when I consider inside movable insulation (Rows highlighted in yellow) and less significant when I consider outside movable insulation (Rows highlighted in green) as shown in the table. I tried adding the material using both "Material" and "Material:NoMass" classes but the issue still persists.
2- If I consider inside movable insulation, then the results are completely off. It seems there is an issue with the heat balance for the movable insulation. I am reporting the node temperatures in addition to the inside and outside surface temperatures of the roof. When I check these results, I get some temperature values for inside and outside surface temps but for all the roof nodes (including node 1 and last node) the temperatures are always 23 C which I think is the initial temperature. Do you think this issue is related to the materials I am using as part of the roof construction that could influence the heat balance? could it be related to the heat balance algorithm (i.e. CTF vs CondFD) as I can see everything related to CTF in the C++ code in this link link text. Also could it be related to the surface convection algorithm (inside/outside)? I am using TARP for inside and Adaptive for outside.
3- You can notice that when I use inside movable insulation (#7) with a schedule of 0 (OFF), this results in exactly the same energy use as when the construction has no insulation (#1), however, this is different when using outside movable insulation with a schedule of 0 (#4).
Theses cases were simulated using the CondFD algorithm as I eventually want to include PCM as part of the construction. However, I tried the tests without including a PCM layer and considering CondFD as well as CTF but both showed similar patterns except that CTF results in a large heating energy use (39,267 kWh) compared to the small figure (66 kWh) from CondFD when the inside movable insulation is considered.
I found some articles that used the SurfaceControl:MovableInsulation approach when the insulation is located inside and outside of a wall assembly so I am thinking maybe I am missing something or doing something wrong! link text.
I tried to make it short but I hope it is clear. Any thoughts or suggestions would be helpful, thanks!
Ammar
Modeling rooftop BIPV
Hello everyone,
I have been working on dynamic insulation systems and I was able to use the surface construction actuator within EMS. Now, I would like to explore the SurfaceControl:MovableInsulation object within energyplus but I am struggling to understand some of the discrepancies that I am getting! I checked the documentation and the two example files that use interior and exterior movable insulation to check how it is modeled. The table below shows a summary of the tests I have been running using the "Material:NoMass" class and CondFD algorithm with a 3 min timestep. I expected that all the matching colors would have similar energy use since I am using the same construction materials but surprisingly they are not the same! some of them are not even close!

1- I notice a big difference between the results when I add the insulation material as part of the construction compared to when I have it in the movable insulation object which is similar to the issue described [here].(https://unmethours.com/question/18475/surfacecontrol-movable-insulation-vs-construction-properties-energyplus/) This difference appears to be significant when I consider inside movable insulation (Rows highlighted in yellow) and less significant when I consider outside movable insulation (Rows highlighted in green) as shown in the table. I tried adding the material using both "Material" and "Material:NoMass" classes but the issue still persists.
2- If I consider inside movable insulation, then the results are completely off. It seems there is an issue with the heat balance for the movable insulation. I am reporting the node temperatures in addition to the inside and outside surface temperatures of the roof. When I check these results, I get some temperature values for inside and outside surface temps but for all the roof nodes (including node 1 and last node) the temperatures are always 23 C which I think is the initial temperature. Do you think this issue is related to the materials I am using as part of the roof construction that could influence the heat balance? could it be related to the heat balance algorithm (i.e. CTF vs CondFD) as I can see everything related to CTF in the C++ code in this link link text. Also could it be related to the surface convection algorithm (inside/outside)? I am using TARP for inside and Adaptive for outside.
3- You can notice that when I use inside movable insulation (#7) with a schedule of 0 (OFF), this results in exactly the same energy use as when the construction has no insulation (#1), however, this is different when using outside movable insulation with a schedule of 0 (#4).
Theses cases were simulated using the CondFD algorithm as I eventually want to include PCM as part of the construction. However, I tried the tests without including a PCM layer and considering CondFD as well as CTF but both showed similar patterns except that CTF results in a large heating energy use (39,267 kWh) compared to the small figure (66 kWh) from CondFD when the inside movable insulation is considered.
I found some articles that used the SurfaceControl:MovableInsulation approach when the insulation is located inside and outside of a wall assembly so I am thinking maybe I am missing something or doing something wrong! link text.
I tried to make it short but I hope it is clear. Any thoughts or suggestions would be helpful, thanks!
Ammar
