Changing indoor temperature with an envelope

Hi everyone ! This is the first time I post something on this page so I hope it will be understandable and that you could help me.


Here is my geometry, I am studying the colored room (first picture). It has 4 adiabatic boundary (3 walll + the roof) and the last one is the exterior wall where I have a custom window.
I am trying to find the air temperature inside my room during the day and to study its evolution with the inclination of an envelope that I placed in front of the window to finally study the indoor comfort. But before I have to study the indoor temperature.

Here is my results with the context wall in a closed position and open position :



PROBLEM :

  1. Is it normal to have the inside temperature between 28°C and 35°C while I import weather from Paris the 1st of November ? ( Outdoor temperature is 15°C)

  2. When we compare both results, temperature decreases logically when the envelope is closed, but I still have this temperature shape penetration as if I did not have an opaque material. I highlight here that the envelope is a context input in my RunEnergySimulation and that I did not manage to give material to the envelope (I tried RADopaqueMaterial and EPTransSchedule but did not work). I would like to clarify that as a final setup I want to place this envelope along the whole facade and not only in front of the window (so i can not use EP window shade Generator).
    I already saw lots of posts about adding materials in similar cases but did not find the solution that could solve my problem. I attach the file so you can have a better insight of the problem.

Thank you in advance for your help.

GrasshopperFile.gh (779.4 KB)
RhinoFile.3dm (45.5 KB)

You are visualizing operative temperature which is a good practice and let you see the effect of mean radiant temperature. Keep that in mind when you are trying to compare it with outdoor air temperature. Is it normal that the operative temperature to get that high? If you don’t let the heat to get out of the room and be replaced by the outside air then then it can happen. Did you set up the airflow controls for this zone so the window opens-up when it makes sense? Otherwise the only place that heat transfer can happen is the conduction through the exterior wall and window.

You can also compare it against your experience. The simulation basically says if you sit in a well-insulated south-facing room in Paris. Close the window and remove the blinds there is a good chance that it gets hot on November 1st when the sun is out. Does that match your expectation?

I have a hard time to understand this part of the question. Can you clarify a little and add some accompanying images if possible?

PS: Welcome to the forum! :slight_smile:

Hi Mostapha

Thanks for reply.

Precision for my second question :

As the shading device, external of the zone, shades over the window opening, it would be expected to have a higher impact on the radiant contribution, lowering the operative temperature significantly, and without making the radiant ‘mark’ in the zone. However, the temperature map clearly outlines the radiant contribution to the operative temperature, despite the shading being down. Why is that the case?

Then another problem is that I did not find how to give material to my shading device. It would not be the same temperature inside if my shading device material is steel or if it is wood for example.
How can I solve this problem and give the material that I want to my shading device ?

Thanks a lot.
Alexis

@Alexis ,
So there are two ways that a shade like that lowers the MRT. The first is the one that you are currently accounting for, which is that the shade lets less sun fall onto the interior surfaces of the zone, thereby lowering the interior surface temperatures and the MRT experienced by people. The second, which you are not currently accounting for, is that the shade blocks sun from falling directly into people, which understandably has a huge impact on the MRT people experience and leaves the “radiant mark” that you refer to.

In order to account for the fact that the shade blocks the sun directly falling on people, you have to plug the shade geometry into the additionalShading_ input of the Indoor View Factor Calculator component. Then, you will see that the “radiant mark” is blocked in the MRT calculation.

Given the way that EnergyPlus models shading, it is not actually calculating the temperature of the shade material so properties like the conductivity or the heat capacity of the shade material do not exist in the simulation. However, the one property that is being modeled is the transmittance of the shade material (set at 0 by default) and you can see that both the Honeybee Context Shading component and the View Factor Calculator that I linked to above have inputs for transmittance schedules.