[esp-r] Re: Emissivity

[Jon Hand]

A recent question about emissivity (see the email below)...

The listing of data is the optical properties. Optical data
is only for the visable and shortwave.  Emissivity of a property
of the materials in the multi-layer construction which is
associated with this optical property.  The QA report which
can be generated from within the Project Manager will tell
you both sets of properties if you toggle the database reporting
to verbose and select at least one thermal zone which includes
a construction using this optical attribute.

At the current time, materials in ESP-r have one emissivity
attribute that applies to both faces of the material. If you
want each side to have a different emissivity then you have
to use two adjacent layers/materials.

A future version of ESP-r will use a database structure that
allows the front and back of a material to have a different
set of surface properties.

Regards, Jon Hand


-----Original Message-----

1. Would any one of you tell me which part exaclty shows the emmisivity of the following double window?
=========================================

DCF7671_6omb :Clear float 76/71, 6mm open mid blnd
# def lyr, tmc lyr, vis trn, sol refl, sol absor, U val
1, 5, 0.76, 0.11, 0.28, 2.8
# direct trn @ 5 angles, total heat gain @ 5 angles
0.611, 0.583, 0.534, 0.384, 0.170, 0.711, 0.690, 0.645, 0.487, 0.250
# refr index, absorption @ 5 angles for each tmc layer
1.52, 0.157, 0.172, 0.185, 0.201, 0.202
1.00, 0.001, 0.002, 0.003, 0.004, 0.005
1.00, 0.172, 0.181, 0.178, 0.151, 0.097
1.00, 0.001, 0.002, 0.003, 0.004, 0.005
1.52, 0.117, 0.124, 0.127, 0.112, 0.077
===============================================



As far as I know, the emissivity should be described for each single glass.

2. That means, there should be two emissivity values on in one double window.
Is it wrong?

Your right answer will be highly appreciated.


Lewis Yook
Team Manager,
Integrated Simulation Unit.
Design and Simulation for Sustainability (DASS) consultants Ltd.

143-834
Venture Support Center 304-ho
632-9 Guui-dong Gwangjin-gu, Seoul, Korea
T. 82.2.913.2585 F. 82.2.949.2585
H. www.dasskorea.com