I assigned three thermal zones and set up all the building construction in OpenStudio. when I run the simulation, I found the U-value of wall, roof and floor do not affect the total energy consumption of my model. No matter what U-value I use, the model output stays the same.
I checked your model. There was no thermal zone, construction set, and schedule set assigned to two of the spaces you had. After applying some values from your library (I picked them randomly since I don't have enough info about your model's properties), I increased the thermal conductivity of your "Netzero wall", which is the main wall assembly in your model and the total energy consumption bumped up accordingly. So, you should double check all the spaces you have and make sure correct properties are assigned to them. The rest of the model seems to be correct.
Asked: 2018-12-09 21:18:53 -0500
Seen: 272 times
Last updated: Dec 09 '18
It's possible that either constructions are not assigned correctly, or HVAC is not set up correctly so that it is not being affected by envelope (like missing thermostats).
Can you send your files? Especially the E+ IDF file and the errors and warnings file.
Thank you both of egillmor and Ehsank for replying. here is my model: https://drive.google.com/open?id=1Npl...
also, when I export the model to IDF file, it says two of the spaces cannot be converted as they do not have a thermal zone. These two spaces are the overall layout of the building so I did not assign any thermal zone to them. Is it a problem?
warming:
Warnings occurred on translation to EnergyPlus
Warning: Space Space 101 is not associated with a ThermalZone, it will not be translated.
Warning: Space Space 1 is not associated with a ThermalZone, it wi
I don't have the software to open a .rar file on this machine, but yes that is a problem.
This is an old tutorial but I think it's still valid. http://nrel.github.io/OpenStudio-user...
Dear egillmor,
here is the link for all the file: https://drive.google.com/open?id=1QEO...
Done, I have set up all the thermal states and thermal zone. thank you. my result of energy consumption is double now. is it normal?
I took a look and the spaces 101 and 1 may be interfering with your other spaces as they are overlapping the other spaces. I suggest deleting those altogether. You can have a thermal zone with multiple spaces, but a space with no thermal zone won't translate its loads to an HVAC system.
I did what you said and the result changes slightly. the building area 19,075 ft^2
R34 roof +R16 wall results 2,639,367 kBtu
R60 roof +R40 wall results 2,633,605 kBtu
As the insulation increases, the energy consumption should go down by a bigger margin.
Well at least it is changing now, so you know it's working. Whether the model is right or not is a complicated question that has a lot more variables.