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Cob mixture in DesignBuilder

asked 2025-10-30 02:50:35 -0600

MrBlue
11 ●1

updated 2025-10-30 09:11:01 -0600

Aaron Boranian

14460 ●92 ●25 http://bigladdersoftware.com/

Hello, I am trying to create a wall with cob mixture in DesignBuilder. TO make the cob mixture, I will need to specify the fibre such as straw or hemp. How do I implement these fibres in DesignBuilder and also how to I make a new material for the cob mixture with different ratio of fibres and soil?

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answered 2025-11-04 10:55:48 -0600

Denis Bourgeois
3838 ●144 ●8 https://www.rd2.ca

@MrBlue,

Not a DB user, but with EnergyPlus it really boils down to pinpointing reasonable blended values for each material layer in the mix (depending on moisture content) - see ref:

thermal conductivity ... anywhere from 0.1 to 1.0 W/m.K ?
specific heat ... 900 J/kg.K ?
density ... from 700 to 1,700 kg/m3 ?

That's a start. With variable moisture content, you could explore more advanced EnergyPlus options. Hope this helps.

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Thank you so much. I will try that.

MrBlue ( 2025-11-05 01:12:05 -0600 )edit

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Asked: 2025-10-30 02:50:35 -0600

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Cob mixture in DesignBuilder edit