I'm working on a project outside the US, in the Middle East, and curtain wall consultant has chosen a glazing from a European manufacturer who has provided their equivalent to the Solar Heat Gain Coefficient (SHGC) rating per the EN 410 standard: their's is the Shading Coefficient (SC).
My understanding is that this standard is more stringent than the NFRC version referenced by ASHREA, and more appropriate since NFRC is for windows, but curtain walls specifically.
Having reviewed the USGBC/GBCI Global ACP documentation I saw a provision to accept an alternate standard:
"Compliance with the mandatory provisions (Sections 5.4, 6.4, 7.4, 8.4, 9.4 and 10.4) in Standard 90.1-2007 (with errata but without addenda) or USGBC approved equivalent."
Does anyone know if the EN 410 is one such standard for complying to the Mandatory provisions in Section 5.4 of ASHRAE 90.1-2007?
I have also checked CIR's but only found 1 related: https://www.usgbc.org/leedinterpretations/LISearch.aspx?liaccessid=5042
I have also posted this question to GBCI but their turnaround, if experience serves me, is about 2 week (in good times). Hope I can get a faster response here.
Thanks in advance.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5915 thumbs up
December 3, 2012 - 12:21 pm
That should be acceptable. It is not really a matter of stringency. The issue is that the glazing system has been tested by a third party which measured its performance.
Amit Ahiel
12 thumbs up
December 10, 2012 - 2:03 am
Thanks for your response Marcus, and I understand your point about stringency. What I would really like to know is how can I prove the "equivalency" of the European EN 410 standard with the referenced NFRC standard?
The numbers and not different by extremes but the testing methods are different but test the same things, only calling the results different things SHGC(NFRC) and SC(EN 410).
What are your thoughts?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5915 thumbs up
December 10, 2012 - 9:34 am
Does EN410 test for Shading Coefficient (SC) instead of Solar Heat Gain Coefficient (SHGC)? If so you can simply convert one to the other. The SC = SHGC x 1.15.
Amit Ahiel
12 thumbs up
February 12, 2013 - 1:07 am
Thanks for your help Marcus.
Amit Ahiel
12 thumbs up
May 1, 2013 - 6:28 am
Here is an update Marcus.
i did some more research and came across this from the HAP user's manual:
>From the Carrier HAP for LEED NC 2.2 EAc1 Training Manual published by
Carrier:
"HAP uses 'Shade Coefficient, SC' for window solar properties. ... Most
of the fenestration industry uses the 'Solar Heat Gain Coefficient,
SHGC' which is conceptually similar to SC. To convert to the SHGC to SC
simply divide the SHGC by a 0.87 conversion factor."