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Exterior Surfaces Temperature

Posted: Thu Oct 06, 2011 10:07 am
by bashar
Hi. I'm testing some exterior cladding systems and their SRI's. I wanted to know if it's possible to calculate the exterior temperature of different surfaces based on the SRI they have.

Thanks.

Re: Exterior Surfaces Temperature

Posted: Thu Oct 06, 2011 10:53 am
by PCully
Hi,

There are input son CDB for an opaque Construction that allow you to specify Emissivity and Solar Absorptance (or 1 - Reflectance). In this way you can represent the SRI.

I'm not sure how this then relates to the surface temperatures but possibly there are some tests you could run based on these inputs to see if it looks realistic for what you want to measure. (in Vista select any room and go down to surface level and you will see one of the Surface Variables reported is Surface Temperature)

Phil

Re: Exterior Surfaces Temperature

Posted: Thu Oct 06, 2011 11:22 am
by bashar
Thanks Phil, hopefully that'll do it.

Re: Exterior Surfaces Temperature

Posted: Sat Oct 08, 2011 1:07 pm
by bashar
Unfortunately it didn't do all of it. I'm trying to find a way where I can compute the temperature of the exterior finish face of the wall, i.e the face that receives direct sunlight.

It might not be possible since, as far as I know, IES only takes into account the room bounded by those walls, and thus only the interior parts that these walls enclose.

I hope there's a way around it.

Re: Exterior Surfaces Temperature

Posted: Mon Oct 10, 2011 8:59 am
by PCully
sorry I don't think it's possible to get the exterior surface temps from Vista. I don't know any way you'd be able to calculate these yourself either.

Phil

Re: Exterior Surfaces Temperature

Posted: Thu Oct 13, 2011 6:05 pm
by ZapBran
You can't get external temps - all you have is internal temps and the temp from the weather file.