[esp-r] Re: RE : Low-e coatings

[Ian Beausoleil-Morrison]

Liam,

You might be interested in knowing that work is underway by Bart Lomanowski
and John Wright at the University of Waterloo to provide a more detailed
treatment of the heat transfer between panes of glass within ESP-r.  Their
work also considers improving the accuracy of shading by venetian blinds.

Bart is copied on this e-mail and may wish to provide some details as well
as estimate on when his work might be merged into the general release of
ESP-r.

- Ian

Ian Beausoleil-Morrison, Ph.D.
Associate Professor and Canada Research Chair
Mechanical and Aerospace Engineering
Carleton University

1125 Colonel By Drive
Ottawa, Ontario, Canada
K1S 5B6

ibeausol at mae.carleton.ca
+1 (613) 520-2600 ext 3022 (telephone)
+1 (613) 520-5715 (facsimile)
www.mae.carleton.ca




____________________________________________________________________
From: esp-r-bounces at lists.strath.ac.uk
[mailto:esp-r-bounces at lists.strath.ac.uk] On Behalf Of Denis J. Bourgeois
Sent: March 12, 2008 18:26
To: Liam O'Brien; esp-r at lists.strath.ac.uk
Subject: [esp-r] RE : Low-e coatings

Liam,
 
The radiation exchanges between surfaces separated by an air gap within a
construction are not explicitly modelled / simulated in ESP-r - rather the
effective thermal resistance of the air gap in the zone's construction file
(.con) can be adjusted to account for various gases and low-e coatings in a
sealed glass unit. Using WIS or LBNL's WINDOW, you can derive the effective
gap resistance for a given window from the entire unit U value, and
individual glass pane thicknesses and conductivities. You should also tweak
values to account for framing effects (both in .con and .tmc files).
 
Hope this helps,
Denis Bourgeois
 
-----Message d'origine-----
De : esp-r-bounces at lists.strath.ac.uk
[mailto:esp-r-bounces at lists.strath.ac.uk] De la part de Liam O'Brien
Envoyé : March 12, 2008 5:51 PM
À : esp-r at lists.strath.ac.uk
Objet : [esp-r] Low-e coatings
 
Hello,

I want to model a low-e coating on a new window construction.  As far as I
can tell, materials (i.e. glass) are defined as homogeneous in the materials
library, and thus have a single emissivity value.  However, clearly a low-e
coating will cause the glass to have two different emissivity values.  Could
anyone share how they have modeled this?

Also, it would be useful in future versions of ESP-r to have fill gases
other than air.  I know the properties of the air can be changed, but it
would save a step to be able to choose argon or krypton, for example.

Thanks!

Liam O'Brien
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