Hi Mingbo, first of all thanks so much for all your help Ironbug is amazing! I am trying to add two air loops to the same thermal zone but it’s not quite working. It creates both air loops, but it only assigns the thermal zone to the second one, and leaves the first one without any components on the demand side. I’ve tried a bunch of different configurations (duplicating the thermal zone, merging the air loops, etc.) but haven’t had any luck. Is there any way around this? This was the closest I got.
Hi @avril14
No, it is not possible, one zone can not be connected to more than one airloop. You will need to divide your zone to smaller zones, and assign different zone to different airloop.
Hi @MingboPeng, apologies to open this thread again, but I am also trying to insert multiple air loops into a single thermal zone. Checking Unmet Hours, they state at “as of EnergyPlus v8.8, you can indeed have multiple air loops serving a single thermal zone”. For more information about the EP version fix that allows this function, see the Github page here.
Are you aware how I can implement this with Ironbug? I have attached a simplified Grasshopper script of my file, where I am attempting to model an air-source split systems per zone for heating, cooling, and dehumidification, as well as a single centralised MVHR system for ventilation. Multiple Primary Airloops in Ironbug_MS.gh (57.1 KB)
The script correctly generates the air loop with the centralised MVHR in OS, shown below:
The script also correctly generates an air loop per zone for the split system in OS. However, the thermal zones are missing from the loops, as highlighted in red below:
Hi @Stranga, I don’t think the OpenStudio supports multiple air loops for a single zone even the EnergyPlus now supports it, which means Ironbug won’t be able to model it as it is built on top of the OpenStudio.
Hi @MingboPeng, I was told by a NREL research engineer that apparently it can be done through the OS API. Where it needs use of the ‘multiAddBranchForZone’ method instead of the ‘addBranchForZone’ method. Though I have no idea how to implement this.
Thanks @Stranga for letting me know this ‘multiAddBranchForZone’ method. Let me think about it how to implement it and I will let you know once I have something for you.
Hi @MingboPeng, thanks for looking into this so quickly and great to hear that it can be implemented in Ironbug so easily.
I’ve re-installed the Pollination single installer, and then ran the GH model from your last message. But I’m not seeing any settings to “allow multi-airloops” in the ‘thermal zone’ component (please see image below). When I run the script, the zone appears in the ‘DOAS’ loop, but not in the ‘air loop HVAC 1’ loop. Can you please let me know what am I doing wrong?
The new Pollination installer that includes this new Ironbug version has not been released. After installing the Pollination installer, you can download the latest version of Ironbug from Releases · MingboPeng/Ironbug (github.com) and Ironbug installer will override the old version that comes with the Pollination.
I am trying to do this with a group of zones that have zone water-to-air heat-pumps. When i add the additional air loop, i get an error about naming faults within the unitary systems. I checked this in the IDF file and can see that when i add the additional air loop, HVAC system 7 gets coil inlet and outlet nodes for HVAC system 11 and so on throughout all of the zone HVAC unitary systems. could you advise what might be causing this issue?
Ive attached the system and left relays attached where there were zones so you can see how many were attached
The issue was happening before i added the schedule files for humidity control so if the constant setpoint managers are used it should hopefully still give you the error.
The loop i was trying to add was to the 45-55 rh zones which has the top DOAS system as its main loop. The loop i was trying to add was the “additional dehumidification” loop.
Hi @Nicholaskerr
I didn’t find any unitary system in your file, is this the correct one? I am having a hard time following your questions alone with your file. Can you provide me with more information about where and what I should look into?
An obvious issue that I found in your file:
You are creating multiple ThermalZones for the same Honeybee Room (see my screenshot below), which is invalid and would cause some issues. If you need to add the same ThermalZone to multiple air loops, just use the same ThermalZone to another air loop. You don’t need to create a new thermal zone for the same room. You can see my example file above.
Some suggestions:
You are building a HVAC with very complex setups that contains multiple sub-systems, and I would:
Make a dummy model with less than 5 zones as the test model.
Carefully test each system independently to see if each of them runs and the results make sense.
If not, move to OpenStudio Application interface and try to manually create the part of the system that doesn’t run or getting non-sense results. Carefully test and debug it in the OpenStudio Application interface. Then, setup/update the HVAC with Ironbug based on your osm/idf file.
Combine each sub-system together to run with the dummy model.
The last step is adding this system to your real model.
These will help you identify the real issues and fix it step by step.
Hope it helps.
