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architecture-building-systems / hive

Rhino Grasshopper plug-in for quick & dirty building simulation
https://www.food4rhino.com/en/app/hive
GNU General Public License v3.0
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Window Frame Reduction | Clarification #818

Open pedrammrbn opened 1 year ago

pedrammrbn commented 1 year ago

In the code, there is a commented-out variable f_sh for "Reduktion Solare Waermeeintraege" which is equal to 0.9 but is not used in the solar gain computations, or anywhere else for that matter:

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The window areas are directly read off of the building inputs, and not modified. As shown in the output from the <SIA 2024 Room Reader>component:

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And then the input to the <SIA 380> solver component:

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This was further tested by changing the value of the Hive.IO.Building.Building.WindowReductionFactor in the code which resulted in no change in simulation results.

ADDITIONALLY: According to SIA 380/1:2016 there is a separate 0.9 reduction factor for solar gains AND another factor for window frame reduction that defaults to 0.75 if undefined. (SIA 380.1 - 3.5.4.12) These two factors are shown in (SIA 380.1 - P.54 (116))

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So in conclusion? Using the modeled Q_solar provides more accuracy, but perhaps a frame reduction factor should be implemented to account for the difference in window areas.

christophwaibel commented 1 year ago

thanks for the summary! Yes, the conclusion is that we should treat it similar to how we have the floor area reduction: do it somewhere in the Hive building component. Will do it asap