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

asked 8 years ago

kumar.biswajit's avatar

updated 7 years ago

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 8 years ago

updated 8 years ago

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's avatar kumar.biswajit  ( 8 years ago )
3

answered 8 years ago

gokul's avatar

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's avatar kumar.biswajit  ( 8 years ago )
2

answered 8 years ago

willyJohan's avatar

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's avatar kumar.biswajit  ( 8 years ago )
2

answered 8 years ago

Ricardo GAllegos's avatar

updated 8 years ago

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's avatar kumar.biswajit  ( 8 years ago )

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Asked: 8 years ago

Seen: 5,344 times

Last updated: Oct 18 '16