[Equest-users] Roof Reflectance

[Adam Barker]

Absorptance + transmittance + reflectance = 1

Since it is an opaque structure, transmittance = 0 and absorptance = 1 - reflectance = 1 - 0.3 = 0.7

Hope this helps.

________________________________
From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of rakeshdesai at ecpl.co.in
Sent: Friday, January 20, 2012 1:06 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Roof Reflectance

Hi,

As per Table G3.1‐5(c), the roof surface should be modelled with a reflectance of 0.45 if the reflectance of the Proposed roof is greater than 0.7 and its emittance is greater than 0.75. Otherwise, the Proposed reflectance should be 0.3. The Baseline roof should be modeled with a reflectivity of 0.3.

In EQUEST, we can put Ext. Absorptance and not reflectance.

What is the relation between reflectance and absorptance and for base line reflectivity of 0.3, what absorptance value should I put?

Rakesh
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