topic Re: Thermal conductivity reference in Modeling

Thermal conductivity reference

Tom Krowka — Wed, 01 Aug 2012 16:15:33 GMT

Anybody know where I can find a good reference for the thermal conductivity, density and heat storage capacity for various materials. I know some are included in the catalog in the energy simulator, but would like some additional materials. For example, 12" CMU block filled with concrete, fiberglass insulation, etc.

Thanks.

Re: Thermal conductivity reference

Erwin Edel — Thu, 02 Aug 2012 07:53:49 GMT

http://en.wikipedia.org/wiki/List_of_thermal_conductivities

In NL we have a free tool from Rockwool that allows you to calculate Rc values. Maybe some one of your local market insulation manufacturers offer a similar solution.

There's a few standardized norms we work with: NEN EN 12524, NEN EN ISO 6946 and NPR 2068. Again, I'd assume your part of the world has something similar set up.

Re: Thermal conductivity reference

Tom Krowka — Thu, 02 Aug 2012 12:43:20 GMT

Have been searching but have not come up with anything comprehensive. Just bits and pieces.

Re: Thermal conductivity reference

Laura Yanoviak — Thu, 08 Aug 2013 16:37:50 GMT

www.esru.strath.ac.uk/Documents/89/thermop_rep.pdf

This is the most comprehensive source I have found, although it is from the UK. I hoping others may have more to add...

Re: Thermal conductivity reference

Tom Krowka — Thu, 08 Aug 2013 20:52:30 GMT

Seems to me this should already be included in the program.

Tom

Re: Thermal conductivity reference

Laura Yanoviak — Thu, 08 Aug 2013 21:30:51 GMT

Many are included, but certainly not all.

Re: Thermal conductivity reference

Anonymous — Fri, 09 Aug 2013 02:08:32 GMT

A great starting point.
But included in this document are some sobering assessments:
Some of which:
"• The sources of much of the data are not identified, and little information is given on the underlying
experimental conditions. As a consequence data merging is an uncertain process because it is often
impossible to ensure compatibility between different entries.
• It is suspected that much of the agreement that does exist between the different data-sets can be
attributed to a high degree of historical ‘borrowing’ one from the other. This in turn may lead, erroneously,
to an optimistic assessment of the inherent uncertainty.
• Many values are quoted without any statement as to whether they correspond to single or multiple
measurements. A random inspection of several referenced works would suggest that values are usually
derived from the work of a single researcher on the basis of a small sample size.
• Many of the data values are derived from work carried out with non-standard apparatus and from a
date which precedes modern standards of equipment and operation.
• No guidance is given on the variation in properties such as density and internal structure inherent in
the production of many building materials."

Re: Thermal conductivity reference

Anonymous — Fri, 09 Aug 2013 11:39:37 GMT

It really depends what you need...what you are doing...

If you are doing some drafting you can use general data which you can find in books, specialized thermal calculation software and internet...

But as You approach to detail modeling You need correct data...
I always make contact with firm that sells material and ask for specific data that i need. Every material should be tested according to standard in your country. Independent laboratory with right equipment does this job...

And, doing this for some time, you will build unique database of materials which will be best for you...

One day everything will be BIM and you will just pick up material from internet database and everything will be loaded automaticly in Archicad...