How to Get CondFD Surface Heat Capacity Output?

asked 2020-06-01 10:25:17 -0600

edriawan
56 ●2

updated 2020-06-01 11:06:32 -0600

Aaron Boranian

14155 ●83 ●24 http://bigladdersoftware.com/

I am doing a simulation of a standard room with four walls.

From here I am informed that EnergyPlus 8.9.0 can give Surface Heat Capacitance as an output with Conduction Finite Difference algorithm.

I think I have done it all, yet in Output:Variable I can not find the "CondFD Surface Heat Capacitance Node 'i'" as I expected. Meanwhile, all other CondFD output such as "CondFD Surface Temperature Node 'i'" and "CondDF Surface Heat Flux Node 'i'" are all present.

What am I missing?

I did the input on IDF Editor on EnergyPlus 8.4.0 firstly as that was the version I had on my PC. But then, after I read that I can have Heat Capacitance on each node as an output on version 8.9.0, I installed it and used IDF Version Updater to make my 8.4.0 IDF to the 8.9.0 ID. I expected to get that Surface Heat Capacity on Output:Variables afterwards, but as I mentioned above, it does not appear. Is this situation played the part hence I have to redo all the input with EnergyPlus IDF Editor 8.9.0?

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answered 2020-06-01 11:57:11 -0600

Aaron Boranian

14155 ●83 ●24 http://bigladdersoftware.com/

The output variables are actually for the outer half or inner half of each node -- not for the whole node. If EnergyPlus can simulate your input file, it can also generate a report data dictionary (RDD) that lists all possible output variables.

I should also note that if you were originally working in EnergyPlus 8.4.0, you should refer to the documentation of EnergyPlus for that version. Various new features or input field changes occurred from v8.4 to v8.9, which is why you have to use the IDF Version Updater IF AND ONLY IF you want to simulate in EnergyPlus 8.9.0. It looks like v8.4 can apply conduction finite difference calculations, but it doesn't have the half-node heat capacitance output you're interested in, so you made the right choice in updating the input file.