EP-construction layer by layer temperatures

energy

#1

Hi all,

Does anyone know if it is possible to output the annual hourly temperatures between the layers in a EP-construction?

I’m interested in the output in the context of knowing the annual temperature distribution in a window

Thank you


#3

@tobiaspedersentsp,
If i understood right, your best friend will be THERM . Check for many of the examples in Hydra.
A second option is using a component i wrote, but still in development, that can give you the internal temperatures per material layer. Attached an example of it. The component is located in the HB WIP tab (133).
Hope it helps,
-A.
CondensationCalculator_4_Forum.gh (489.0 KB)


#4

Yes you understood it right - thank you very much !


#5

I’ll add that all THERM simulations are steady state (so they assume that the interior + exterior boundary conditions have been that way for a significant period of time, like a few hours). This may still be good for your purposes but it’s just something good to be aware of as it’s a critical difference from E+ simulations, which are transient.

As long as you are good with the steady state assumption, you can model a wide array of cases with THERM, including ones with solar radiation, which you can account for with the Custom Rad Environment component.


#6

@chris - thank you for your response

Quick question:
Given that a transient simulation using EPW would be preferable do you have any suggestions of how one might do that (or if it is even possible)? Otherwise I’ll make a “worst case scenario” steady state investigation.

To elaborate, I’m investating possible radiation asymmetries of a Complex Fenestration System, where the shading layer is mounted between the glass layers.


#7

@tobiaspedersentsp ,
I’ve had a need to do this type of thing at one point when we had shades between glass panes overheating to really high temperatures. If you were investigating a winter design condition without sun, I would say that you should use THERM but, for a condition like this where the orientation of the glass in relation to the sun is important, you should probably use another method.

In my case, we were able to get a decent approximation of the temperature of the shades by modeling the space in between the two panes of glass as am EnergyPlus zone and making sure that the constructions on each side of the zone matched the glass on either side of the gap. We then added some interior blinds into the zone using the EnergyPlus Window Shade Generator. We used the resulting interior surface temperature as an estimation of the temperature of the internal shades. In your case, you can use the difference between the two sides of the shade glass to get a sense of the thermal asymmetry.

For clarification, I should say that there’s no EnergyPlus output for the different temperatures within a construction but, by breaking your construction into zones like this, you can get decent estimates of those numbers.

Lastly, I’ll mention that the method above was hacky and not necessarily endorsed as state-of-the art but it demonstrated that high temperatures were possible given the setup of our case. If you really need to do state of the art stuff, you should probably use a combination of radiance to get radiation fluxes and then send those fluxes through an OpenFOAM simulation to account for the air circulation in the cavity. However, the learning curve to do that is at least a year whereas you can get the rough approximation from E+ in a day or two of setup and validation.


#8

Thank you very much Chris