Unitary HP System on Supply Side


How would I go about making a unitary HP system like this on the supply side? It is tied to a heat pump loop with a central cooling tower


@Elliot_Glassman Could you attach an example osm file with one or two zones for me to test?


This model may have more zones than you wanted, but it has the system that I am trying to replicate

Large Office Building CZ 5A.osm (1.2 MB)


@Elliot_Glassman, I have added the Unitary System. Please update the Ironbug with following package.
Ironbug_UpdatePkg_v0.0.12.2.zip (742.5 KB)

Here is an example built based on your file.
UnitarySys.gh (619.2 KB)

I only did one test with above file, it runs successfully. But please keep me posted if you find anything that doesn’t work as expected.



Amazing! Thank you for the update. Works like a charm


Hello @MingboPeng,

Is there a way to get this update for the OpenStudio 2.8 version, please?.




Here is the update package for 2.8 Ironbug_UpdatePkgForOps2.8_v0.0.12.2.zip (743.3 KB)


Thank you very much @MingboPeng!


I think I may have found a bug… when I try to specify the Glychol Concentration, the condenser water loop throws an error. Running it through a number container first does not help.

Also, is there a way to create a fluid cooler? I only see cooling towers.


It seems the ObjParams components failed to guard the input type for Glychol Concentration.
In this case, openstudio is expecting the integer for the input value.
I will look into the code and try to fix it. but for now you can pass the value via “Integer”

Evaporative fluid cooler is not added yet, but if you could provide an example with a basic settings, that’d be great, and I can add it over the weekend.



Yeah the only problem is when I pass 0.4 as an integer, I get 0!

What can I provide you as an example? I am basically trying to change this Unitary system to have a fluid cooler not a cooling tower. Let me know what is most helpful to put together for you.


Hi @Elliot_Glassman, I have added an integer type in objParam component, all values will be automatically converted to integer when it is needed.

I have added fluid cooler in following update package.
Ironbug_v0.0.12(20190623update).zip (264.1 KB)

Please let me know if it works.


Hi Mingbo,

Thanks for the amazing update.

Is it possible that something in the plant loop branches may have broken in this update? For some reason all my plant loop components are only showing one branch now despite multiple inputs, and the OS file is missing the other branches (needless to say, the simulations won’t run)


You are right, I updated the plantBranches component last week as well, and I did break the old component.

But here is a fixed update, please let me know if this works.
Ironbug_v0.0.12(20190624update).zip (260.7 KB)