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[EnergyPlus_Support] Re: Revisiting SRI modeling and calculations

That sounds correct to me. In most cases, product data states thermal emittance not solar emittance. Here's the Cool Roof Rating Council database:


--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Jim Dirkes <jim@...> wrote:
> Dear Forum,
> I thought I had this topic (modeling SRI values in E+) well understood, but now I am unsure.  Please let me know if the approach below is sound:
> *         The technical data for a "cool" roof generally notes solar reflectance and solar emittance along with an SRI value
> *         EnergyPlus's Material object wants to know thermal absorptance, solar absorptance and visible absorptance (plus other properties)
> As far as I can tell,
> 1.       solar absorptance for E+ = 1 - solar reflectance from technical data
> 2.       thermal absorptance for E+ = solar emittance from technical data
> 3.       visible absorptance is anyone's guess, since it's not mentioned in the technical data.
> Does that sound correct?  Thanks in advance!
> James V Dirkes II, PE, BEMP, LEED AP
> www.buildingperformanceteam.com<http://www.buildingperformanceteam.com/>
> Energy Analysis, Commissioning & Training Services
> 1631 Acacia Drive, Grand Rapids, MI 49504 USA
> 616 450 8653


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