[esp-r] Re: thermal bridges assessment

[Jon Hand]

Here is a sample:
# 
*bridge_start,0.000,0.000,0.780,0.000  # user fraction,losspercent W/K, total heat loss W/K and total UA
 W/K
*ukt_bridge,user-defined,  2.000,  0.3900  # type length psi value
*end_bridge

In this case there is a user-defined linear thermal bridge that is 2m long and with a
psi value of 0.39 W/mK.  Thus the 3rd item in the *bridge_start line is 2x.39.

The first two numbers in the *bridge_start line are used in building code compliance
to set a percentage of the overall heat transfer to assume for thermal bridges. For
most folk just keep these two at zero (the interface offers a choice for this).  

The last value on the *bridge_start line is the UA for the zone. In the above  example
it is zero because the automatic facility in the interface was not used.

Regards, Jon Hand
________________________________________
From: olivier bounhoure [olivier.bounhoure at gmail.com]
Sent: 19 December 2012 20:59
To: Jon Hand
Cc: Geissler Achim; esp-r at lists.strath.ac.uk
Subject: Re: [esp-r] Re: thermal bridges assessment

Thank you Achim and Jon,

As far as I understand I should reorder my priorities and focus on using linear thermal bridges. Swimming in fortran is one of my hobbies, nevertheless I can not spend the next weeks full time on the multigridding feature :) So I will try to dig a little bit more in 2013

About the linear thermal bridge I would like to know the meaning of the coefficients in the "*bridge_start" line. Is it documented anywhere ?

Best regards,
Olivier


2012/12/19 Jon Hand <jon at esru.strath.ac.uk<mailto:jon at esru.strath.ac.uk>>

The 3D conduction facility of ESP-r is rarely used - for most people knowledge of it has
become obscure/lost.

ESP-r is able to deal with linear thermal bridges (so-called psi values) as an approximation
based on some steady state assumptions.  The zone geometry interface (prj) can detect different
join types for surfaces in a zone and allow you to associate a psi value per m of each of these
types of lengths.  Heat transfer via linear thermal bridges is reported in the zone energy balance.

-Jon Hand
________________________________________
From: esp-r-bounces at lists.strath.ac.uk<mailto:esp-r-bounces at lists.strath.ac.uk> [esp-r-bounces at lists.strath.ac.uk<mailto:esp-r-bounces at lists.strath.ac.uk>] On Behalf Of Geissler Achim [achim.geissler at fhnw.ch<mailto:achim.geissler at fhnw.ch>]
Sent: 19 December 2012 16:21
To: olivier bounhoure; esp-r at lists.strath.ac.uk<mailto:esp-r at lists.strath.ac.uk>
Subject: [esp-r] Re: thermal bridges assessment

Hi Olivier

I'm afraid you are not the only one with problems with this feature. Some time ago, I also tried to get this up and running, but was also unsuccessful. I managed to get past the core dumps at one point, but was not able to generate useful results. There is a Masters- or PhD thesis as far as I remember, you would need to search on the ESRU site, however. I wouldn't expect this to tell you how to make it work, though.

If you are prepared to code-crawl and find out what is wrong, I would be interested in the solution, anyway.

Best
Achim



Von: esp-r-bounces at lists.strath.ac.uk<mailto:esp-r-bounces at lists.strath.ac.uk> [mailto:esp-r-bounces at lists.strath.ac.uk<mailto:esp-r-bounces at lists.strath.ac.uk>] Im Auftrag von olivier bounhoure
Gesendet: Mittwoch, 19. Dezember 2012 17:00
An: esp-r at lists.strath.ac.uk<mailto:esp-r at lists.strath.ac.uk>
Betreff: [esp-r] thermal bridges assessment

Hello,

I'm looking for elements about thermal bridges assessment. I did not find any information about multigridding and the dedicated exemplar (namely constr/adapt/cfg/g3d.cfg) does not run "out of the box", unfortunately. Actually it crashes with a segmentation fault. I do not know if it comes from an unpropper model or from my program installation.
1) Is there a tutorial / paper / note on the way of making proper use of the functionallity ?
2) Am I the only one having an issue with the exemplar ?

Sincerely,
Olivier