Calculating solar reflectance using Ecotect

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Hello,

Has anyone used Ecotect to analyze solar absorption/reflectance for a surface , for example a building fa?ade? Using Ecotect, it is possible to calculate the incident solar radiation values but I am more interested to find if the software could be used to determine the solar reflectance/absorption values to help compare various design options.

Any thoughts or suggestions on this issue is very much appreciated.

Thanks,

priya premchandran, LEED? AP

Priya Premchandran's picture
Joined: 2011-10-02
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Hi

What you describe sounds like an impossibility for all software, and is certainly I think impossible for Ecotect. Perhaps I am misunderstanding the question? You seem to be asking whether Ecotect (or other software products) can measure the physical properties of a building facade? Building physical properties are input parameters to simulation programs and to Ecotect. One needs a field instrument to do this, not a piece of software..?

m

Michael Donn's picture
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Joined: 2011-10-02
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Priya,

It is not possible to measure the physical properties of a material through
a software. As Michael said, it needs to be measured through field
instruments. However, you seem to want to compare the effects of absorptance
and reflectance of different facade materials for a given design problem. Is
that correct? If yes, you can definitely simulate the reflectance and
absorptance of a given material using Ecotect. This page gives complete
details on how to do it: http://squ1.org/wiki/Solar_Absorption.

You can define the characteristics for two different materials and apply
them one by one to the facade under investigation to see how it makes a
difference. However, I am not too confident of Ecotect's capabilities in
this regard yet. For example, I modified the external layer of a material
assembly (for a wall) and recalculated physical properties through Ecotect.
The solar absorptance did not get updated. This leads me to believe that the
feature is not reliable. If you are familiar with IES Virtual Environment,
then that is a much better tool for studying the changes in material
assemblies. If you're just interested in the heat gain/loss, thermal lag
kind of stuff, a very simple tool that you can use for free is OPAQUE (
http://www.energy-design-tools.aud.ucla.edu/). This link has other useful
tools that you might already be using (they are so helpful!).

Hope this helps.

Thanks,

*Anupam Jain*

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