EMS as Additional String



Dear Community,

I am trying to overwrite the EP Transparency Schedule of a simple shading by EMS coding as an input to E+ engine.

I defined two sensors: one is the sunlit fraction on window, and the other one is the indoor operative temperature. I controlled these two sensors through available actuator in E+, and it seems Honeybee recognizes the EMS perfectly and changes the Trans.Sch according to the sensors, but the operative temperature does not change when you add/remove the EMS string.

This picture shows the results when I used EMS and it changes the Transparency schedule default to what I expected perfectly …

But here when I disconnect the EMS string, the schedule will return to what I connected manually as a fraction of ‘1’ which means completely transparent for the whole year, but the operative temperature still remains the same…


test03-EMS.gh (636.9 KB)



I would start by checking the values that eventually effect the operative temperature and go backwards to find the source of the results. Did you try to check the amount of radiation that passes through the window and surface temperature of the windows in both cases? That should be a good starting point.

I didn’t open the file but you should also keep in mind that the calculation is done for the center of the zone so it will depend on the view factor from the center point to this window.


Thanks @mostapha for your reply,

Both window outdoor temperature and the energy flow are the same which shouldn’t be…

This is excluding EMS string…

And this is including the EMS…

test03-EMS.gh (624.4 KB)

BUT, when I copy the overwritten schedule into a panel (the one that I obtained after implementing EMS) and import it to the EPTransschedule of the Hb context component like a normal case, the results will change proportionally…

Has anyone did a simulation of electrochromic window?

From your tests it seems that you may not be setting the right parameter to change the transparency of the context shade. Just knowing that E+ has a lot of outputs (some of which are not too helpful), the Weighted Shade Fraction Schedule might not have any real bearing on the simulation that you are trying to run here.

The UnmetHours forum might also be a better place to ask questions that are this deep down the rabbit hole of E+. You are definitely stretching my expertise here :slight_smile: