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Forum discussion

NC-2009 EAp2:Minimum Energy Performance

SHGC of a double skin curtain wall

Chaan Ah Bahk

LEEDuser Basic Member

19 thumbs up

July 19, 2011

Hi All, I'm working on a project building with double skin facade, and this double skin facade system is equipped with an automatic shading device in the cavity space between the glazings. This curtain wall has two SHGC factors, i.e. 0.25 when the shading is on and 0.5 when the shading is off. This is also indicated on the NFRC label. Question; Which factor am I supposed to input in the energy simulation, 0.25(better than the baseline) or 0.5(worse than the baseline)? Is it correct to approach in a way we model the interior blinds, i.e. input 0.5, then, give in the schedule when the shading is on?

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Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Mon, 09/19/2011 - 16:23

I am a bit confused. SHGC is a characteristic of the glazing itself, independent of any shades. Unless the glazing characterisitcs change, the glass would be modeled indepemdently of the shades. I think your last question points you in the right direction.

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