I’m modeling a project of multiple zones and I have an issue when I add ZoneName list. Here is a simplified version. I have Zone 2 through 5 with a total cooling loads of 135,637, 38,674, 72,725, 65,324 kWh for each zone, respectively. As shown in the next two screenshots. 01.png 02.png.

When I changed the zone name using HB Mass to Zone, It assigned the right new name to each zone with no issues. I changed Zone 2 to “Kitechen2nd”, Zone 3 to “Kitechen1st”, Zone 4 to “DiningW”, and Zone 5 to “DiningE”. As shown in the screenshot. 03.png. However, when I looked to the result, I saw that the new names don’t represent the correct zone. For example, Zone 2 has a total cooling load of 135,637 and when I changed the name of the zone to be “Kitechen2nd”, it shows a cooling load of 65,324. as shown here. 04.png.

It’s weird because HB assigned the new names correct but when I readEPresults, the values were assigned to different zones. An idea? Did I miss something?

This might be the same issue as this one:

I’m sure Chris will get back to you on this issue soon.


Back to the same issue. Here is an example for the issue. I’ve two zones and when I checked the ZonenAttributeList > Name as showing in the image, the large zone is ZONE_3 and the small zone is ZONE_4. The 3D_Chart shows that ZONE_4 consumes more energy than ZONE_3. Results are not assigned to the right zones!!! Anyone know why I’ve this issue? (577 KB)

I’m trying to find when this weird issue happens. It has nothing to do with the naming as I thought.

It happens when I model several zones but to make it clear, here is an example of two zones only, which are named as “large” and “small”. The first screenshot shows the 3D_Chart cooling load results. The large zone in top and the small zone below it and the title of each chart is correct. When I disconnect the HBZone from the HBSolve_Adjac and reconnect the small zone first and the large zone second, the results are different as shown in the second screenshot. The title of the top chart still shows “large” but it has the small zone result.

When one zone passes through HB_GlazingCreator and the other zone has no windows (connects directly from HB_Mass2Zone, the top chart titles as “large” but it has the result of the other zone as shown in below. In this case, it does not matter which one is connected first.

Any idea? Please help


I’m sorry for the incredibly late reply here. I realized that the issue results from how OpenStudio names the ideal air load systems. Specifically, OpenStudio does not write the name of the zone into the system name and this is causing the result reader to misinterpret the results. Let me see if I can fix it now.


Ok. I figured out why this is happening but I haven’t found a solution yet as it’s largely an issue with OpenStudio. It seems that Openstudio will assign numbers to the ideal air loads systems based on the order of in which zones are connected to the OpenStudio component. However, OpenStudio will write the zones into the IDF using a different order that I have not yet been able to understand. Let me take some time to figure this out.

Ok. I fixed the matching issue for ideal air loads systems:…

That was easier than I realized. I just needed to include the zone name in the name of the ideal air loads system. So everything with your issue here should now be fixed.

Now I just need to do the same for some of the other HVAC system types that have zone-level outputs.

Thank you Chris

Thank you, Mohammed, for finding this bug. I fixed the labeling of results for other HVAC results as well:…


I think the issue is also with read EP surface result component. I’m not sure but I remember I had an issue with it before. I will check it and let you know. Thanks,


If there is an issue with the ReadEPSurfaceResult, it should be different than the one that twas affecting ideal air loads as I see that component is still using surface names to match results with the HBSrfs. Still, please keep me posted if you find anything.