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Fenestration properties dynamic change [closed]

asked 2016-05-02 04:18:12 -0600

FSilenzi gravatar image

Is it possible to model in OS or E+ an innovative kind of rotating windows that mantain constant transmittance but have different emissivity value for each side, in order to maximize or minimize sun heat gains depending on the season?

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Closed for the following reason the question is answered, right answer was accepted by FSilenzi
close date 2019-03-08 03:48:17.110136

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answered 2016-05-02 10:52:45 -0600

updated 2016-05-02 19:26:44 -0600

Sounds like you want to model the effect of actually changing the surface a low-e coating is on, between surfaces two and three. Cool! Got VC? ;) You can certainly model it, we'll leave the question of whether it's physically possible over here, on the side for a sec. ;)

You could use the SwitchableGlazing object to model this, and then use the SimpleGlazingSystem for the window materials. Moving the low-e coating around will affect the u-value and SHGC together, so you could use Window or Optics to compute the Big Three (VLT, SHGC, U) for two different IGU configurations, make the two materials, make two constructions that use these materials, and apply them to a window subsurface with a shading control.

P.S. You don't even need to use Window or Optics, if you have a sense of what these parameters should be (perhaps you have mockups you've tested yourself, or have inferred the parameters) you can simply plug them into the SimpleGlazingSystem materials.

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Thanks for the reply! Physically it is indeed possible, a couple of prototype have been fully developed and tested. Anyway when you talk about Window or Optic what are you talking about? Other software? If so, and if I am not mistaking I believe you are, it could be quite a painful solution since I have no experience about those and I have no time to learn them since the deadlines are so close in time :(

FSilenzi gravatar image FSilenzi  ( 2016-05-02 15:45:18 -0600 )edit

Yes, Window and Optics are applications produced by LBNL that allow you to make up your own IGU definitions, based on tested materials (glazings, films, and screens) in the International Glazing Database. They are actually pretty easy to use once you push past the initial GUI learning curve. But I get it, time is of the essence. Option two is to create materials with VLT/SHGC/U values based on what you THINK they should be. Make sense?

rpg777 gravatar image rpg777  ( 2016-05-02 16:37:26 -0600 )edit

I should have access to almost every data about the prototype and final product, so with a little help from the community I think it would be less painful than I thought. Basically I need to obtain VLT/SHGC/U to start the work, correct?

FSilenzi gravatar image FSilenzi  ( 2016-05-03 04:34:49 -0600 )edit

I have experimented with moving the low e coating from the #2 surface to the #3 surface using Window. I import the Window definitions into the model. There is a noticeable difference in results between using the Window definitions and simply using VLT/SHGC/U.

Chris Jones gravatar image Chris Jones  ( 2016-05-03 07:51:09 -0600 )edit

@Chris Jones, the most accurate results will always be from a rigorous evaluation of the actual makeup of the IGU. My suggestion to simply use the big three parameters was because @FSilenzi mentioned he did not necessarily have time to learn another program. Of course this approach requires one to have a process for estimating the parameters, and to accept/document/justify the potential(s) for error.

rpg777 gravatar image rpg777  ( 2016-05-03 09:38:58 -0600 )edit

answered 2016-06-10 02:37:06 -0600

FSilenzi gravatar image

Ok I managed to do this by setting a simple glazing system with the informations derived from Window and then running two simulations.

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Asked: 2016-05-02 04:18:12 -0600

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Last updated: Jun 10 '16