[esp-r] Re: How to make this glass? (TMC)

[Jake Zwart]

These are notes I made for myself a few years ago when faced with making
windows that were more easily modeled outside esp-r.  I expect not much in
this area of esp-r has changed.

Jake

Advanced Windows modeling
See the FAQ pdf file.  First generate the window using Windows 5.2,
documentation talks about Windows 4.1 or WIS.  Well after I wrote this
section I noticed that NRCan has put a Canadian Windows modeling program on
its website that may be worth checking.  UW is working on a better window
model implementation in esp-r.

Windows have both an insulating function and a transparent function.  ESP-r
treats these separately for solar gains and heat loss.

  1.. The optics database is used for the solar gains.  Use the program
Window 5.2 from the US government (LBL) for the transparent properties of
the windows.  This program gives the angle dependent transmission values.
  I think ESP-r can import directly (it says it can from an earlier
unsupported version of Window) but I have not tried this.  Someone suggested
using WIS, but I have not been able to make this program work.  (Haven’t
tried to hard, nor had the incentive to try.)
  Jon Hand has an import from Window 5 on his to do list.
  2.. The multilayer construction is used for the heat loss.  If the window
is argon, it needs a higher R-value for the air layer than the default 0.17.
I used 0.25 for ½” of argon.  This was scaled from argon conductivity as
compared to air with the values taken from Window 5.2.  Presumably similar
scaling can be done for krypton or mixtures.
  Even then the U-value is incorrect.  The Solar absorptance and IR
emissivity do not seem to affect the U-value.
  I played with the air (ID 0) resistance to try and match U-Values.  This
is also what Jon Hand recommends.
  Another time I just played with gap thickness to get the R-value that I
wanted.
  The Uvalue should be accurate, at least according to Jon Hand.
  3.. More information in the FAQ pdf file.
  4.. Types of glass can be obtained from your glass manufacturer.
Editing Windows
When editing windows in the

m browse/edit/simulate

c composition

b constructions

….

menu, to change from one construction to another with differing optical as
well as insulating properties, then the display of the optical properties
does not change until you go into the

b database maintenance

d constructions

a browse or edit this file

> save database

What I don’t know is if this is required for only the correct display or
also the correct values for the calculations.  So better safe than sorry.

Jon’s response below

The recommended place to change a surface attribute from

one construction to another is in the

zone geometry->surface attributes facility rather than in the

zone construction menu.



If you make the change in surface attribues it detects that

both the zone geometry, construction and tmc files need to

be updated.



Every once in a while a change from an opaque construction

to a transparent construction will generate confusing messages

that indicate that the tmc file might not have been written out

correctly. In such cases it usually works to use the up-date

all constructions option at the bottom of the zone constructions

file list.

  -----Original Message-----
  From: esp-r-bounces at lists.strath.ac.uk
[mailto:esp-r-bounces at lists.strath.ac.uk]On Behalf Of Lewis Yook
  Sent: Tuesday, 27 November, 2007 19:50
  To: ESP-r User Forum
  Subject: [esp-r] How to make this glass? (TMC)


  Dear Everyone.



  I am trying to make a new multilayer construction in esp-r.



  The attached picture shows the multilayer of the glass which I want to
apply in my project.



  The thing is that 'the sun block film' (red thin layer in the picture)
absorbs 75% of solar heat (in average).



  This heat, then, is emitted from the film surface to the adjacen zone.



  It warms up the temperature of that zone.



  Do you think I can simulate this case using a new TMC ?



  Your teaching will be really appreciated.



  Thank you for reading.



  Sincerely,



  Lewis Yook

  Team Manager,

  Integrated Simulation Team.

  Design and Simulation for Sustainability (DASS) consultants Ltd.


  139-743

  31-dong(Business Incubator Center) 103-ho,

  Seoul National University of Technology

  174 Gongreung 2-dong Nowon-gu, Seoul, Korea

  T. 82.2.913.2585 F. 82.2.949.2585

  H. www.dasskorea.com


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