Psych Chart - "less" Passive Strategies listed

Hi all,

Relatively new to psych charts here but is there a reason the LB passive strategies (red circle) has less passive strategies available than the original Ladybug passive strategies (blue circle)? I’d like to use the latest LB modules but am missing these other strategies.

Perhaps this is somewhat related to this post about adding shading as a passive strategy: Passive Strategy List - Psych Chart - #2 by chris

Adding string text for Humidification Only and Dehumidification Only did not work for me.

Let me know if I am missing something obvious. Thank you for your help,

Hi @rxs5160 ,

I didn’t implement “Humidification Only” and “Dehumidification Only” because they are not real strategies that have a physical meaning. If you were to humidify a space by evaporating water, it would also cool the space, doing exactly what the “Evaporative Cooling” polygon does. Similarly, if you were to to remove humidity by using a desiccant, it would heat up the space. If I’m being honest about why I put these polygons in the Legacy plugin, it’s because it was easy for me to implement them in the source code and I saw that Climate Consultant had done it. But, in retrospect, I think this misleads a lot of people into thinking that we have some magic way to add or remove humidity from the air without impacting the temperatures, particularly because so many teachers use the psych chart to teach new students about passive design.

I have plans to eventually add a few more polygons, including a “Desiccant Dehumidification” one, which will show the polygon that both dehumidifies and heats up the air.

After some people asked for it, I’ll also add a “Shade Line” that does not change the overall comfort percentage but gives you a sense of how helpful shade is when it is used with an “Active Cooling” polygon. I described the proposal for this here:

And, if I’m going to add an “Active Cooling” Polygon, I’ll also add an “Active Heating”. But that’s all that I can think of for new polygons and I don’t want to add hypothetical ones that don’t translate into a real strategy that is meaningful for design.


@chris thank you for the background and clarity. Looking forward to future developments and appreciate your help

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