Ladybug psychrometric chart / passive solar heating question


I am using the powerful psychrometric chart component in Ladybug, but have a question that I can’t seem to find an answer to online.

The passive solar heating strategy seems to have a mind of its own. I was using the GitHub file posted by @Chris from 2018 (

When you check Passive Solar Heating, the “comfort zone polygon” is huge, but the “strategy percent of time” reads as a small number (< 3%.). Also, it seems that when Internal Heat Gain is turned on (checked), Passive Solar Heating changes (%’s, as well as the polygon). The data seems to show this as well when viewed in a 3D comfort hours chart (the charts that show a spread of red—comfortable—over time of day for the year).

Any ideas what may be happening? Has anyone come across this before? I couldn’t attach the script here because it says i’m a new user (just created the ladybug–specific iscourse account). You can find the script here instead It is a slightly tweaked version of Chris’s file from GitHub. (psychchart component is clustered)

Thanks for any assistance you may be able to provide - this component is really awesome and is a great starting point for all projects.