Solar Adjusted MRT - effect of different window geo and g-value?

Hey Chris or anyone familiar with the MRT component!

I’m trying to figure out if and how varying g-values (SHGC) of windows in the façade affect (adjusted) indoor comfort in specific locations in a room.

In a hypothetical situation (see image), I have 1 room with 4 façade windows and 4 skylights. The windows have different g-values for which I have list of 8 window transmissivities from the EPlus simulation.

I have 10 test points where I’m interested in measuring the adjusted MRT, i.e the body location input.

Since no geometry can be input for windows in the adjusted MRT component, do the 8 window transmissivities from the EPlus engine have any correlation to their actual position when I input them in the adjusted MRT component?

/Amanda

Attachments:

MRTsituation.JPG, 78 KB
MRTsituation2.JPG, 98 KB

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Permalink Reply by Chris Mackey on December 16, 2015 at 9:06pm

Hi Amanda,

Thanks for posting and it's great to see you taking the components to their limits!

Let me make sure that I am understanding you correctly. If you are trying to test out 8 different cases where all of the windows of the zone have the same transmissivity to see the effect of the building's overall window SHGC on comfort, then your current file looks like it should be correct. However, if you are trying to analyze a single simulation where each window has a different transmissivity, the Ladybug_Solar Adjusted MRT component is not going to be able to help you since its windowTransmissivity input is not built to understand the relative contribution from elements with different transparencies.

If you are interested in this latter case, you can model it using the microclimate map workflow that I developed for my thesis, which will look at the relative contribution of each surface and window element on local MRT. Here is an example of a simple test box that is using this micro-climate map:

http://hydrashare.github.io/hydra/viewer?owner=chriswmackey&for...

If you are only interested in Radiant Temperature, you can use the radTempMtx output from the Microclimate Map component and, if you would like the operative temperature or adaptive comfort, you can replace the UTCI recipe in the example above with the "Honeybee_Adaptive Comfort Recipe".

The micro-climate map workflow will compute a starting MRT from the view factor and temperatures of your zone's surfaces and will pull the SHGCs of your windows from the EP constructions of your HBZones when it computes solar-adjusted MRT. So all that you have to do is assign the SHGCs correctly to your HBZones and the component will take care of the rest.

Let me know if you have any questions and more information on the comfort maps can be found in my thesis document:

https://www.dropbox.com/s/k4r4rd279y4td9n/Mackey_Thesis.pdf?dl=0

-Chris

Permalink Reply by Amanda O'Donnell on December 31, 2015 at 2:29am

Hey Chris,

It is the latter case I am interested, i.e. looking at the relative contribution of each surface on the local MRT. After reading your thesis, it's clear that the solar adjusted MRT is incorporated in the MicroClimate Map component.

Thank you, great work!

/Amanda

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