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Where can I find (such as database) the R-values of different materials?

asked 2016-10-17 08:35:23 -0500

kumar.biswajit gravatar image

updated 2017-06-02 18:22:59 -0500

I am trying to calculate the U-value of different wall sections. That's why I need the R-value database.

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answered 2016-10-17 21:50:14 -0500

updated 2016-10-18 11:48:10 -0500

Here's a list of the resources I would investigate:

  1. ANSI/ASHRAE/IES Standard 90.1 Appendix A
  2. ASHRAE Handbook of Fundamentals, Chapter 18, Table 18
  3. ASHRAE Handbook of Fundamentals, Chapter 26, Table 1
  4. COMNET Appendix D - Construction Materials
  5. OpenStudio Standards
  6. The Building Component Library

The materials in (2) are available in the OpenStudio via:

  1. The On Demand Template Generator
  2. OpenStudio library files (File > Load Library).

Also, the OpenStudio API can be used to get components from the BCL. See these previous questions for more information:

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Thank you very much for the response.

kumar.biswajit gravatar image kumar.biswajit  ( 2016-10-29 20:03:58 -0500 )edit
3

answered 2016-10-17 11:08:34 -0500

gokul gravatar image

Hi, Appendix A (Tables 3.1) in ASHRAE 90.1 has information on the relation between equivalent U-values and R values of wall sections. By general definition, U-value is the ratio of the conductivity to the thickness of a material, and R-value is the reciprocal of the U-value. Hope this answers your question.

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Thank you very much

kumar.biswajit gravatar image kumar.biswajit  ( 2016-10-29 20:06:37 -0500 )edit
2

answered 2016-10-17 12:08:52 -0500

Ricardo GAllegos gravatar image

updated 2016-10-17 12:09:46 -0500

The U value takes into the account the film coefficients on the outside and the inside. For complex walls and roofs, with thermal bridges, there is a publication of ASHRAE that lists numerous structures with their U values, sorry I dont have the reference at hand.

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Thank you very much

kumar.biswajit gravatar image kumar.biswajit  ( 2016-10-29 20:06:12 -0500 )edit
2

answered 2016-10-17 18:29:03 -0500

willyJohan gravatar image

In case you do not have easy access to 90.1. The reference appendices for Title 24 Section 6 include tables giving the U-Values for different wall and roof assemblies developed using the approach outlined in the 2009 ASHRAE Handbook of Fundamentals.

http://www.energy.ca.gov/2012publicat...

starting on pdf page 137

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Thank you for the suggestion

kumar.biswajit gravatar image kumar.biswajit  ( 2016-10-29 20:05:12 -0500 )edit

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Asked: 2016-10-17 08:35:23 -0500

Seen: 2,696 times

Last updated: Oct 18 '16