Relationship between illuminance and thermal behaviour

asked 2021-08-02 01:37:19 -0500

cyber's avatar

updated 2021-08-21 07:09:02 -0500

I am looking for any literature guidance.

Assume that a building has specific properties in terms of material and glass panel window. If I were to increase window to wall ratio to increase indoor illuminance, how would heating and cooling demand change?

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The details in the question are a little general, so I can’t give a specific answer other than to say that changing the WWR and/or window performance characteristics would impact both heating and cooling. If you have a high internal load building that is always in cooling mode then larger windows will likely increase cooling loads. Larger windows may often decrease the heating load with free heating from solar gain, but if the window performance is very bad the extra glazing area could hurt your heating more than the solar gain helps. Could run simulation to test, orientation also matters.

David Goldwasser's avatar David Goldwasser  ( 2021-08-02 15:47:07 -0500 )edit

I would model this; you can find the Window to Wall Ratio measure written by NREL here.

It was actually written by @David Goldwasser!

Simply model a baseline case with a low WWR and a proposed design case with a high WWR. See how illuminance changes (some packages of E+ includes Radiance, if so you should have some daylighting output variables), and extract appropriate output variables to examine heating and cooling demand.

sashadf1's avatar sashadf1  ( 2021-08-02 16:03:28 -0500 )edit