Converting Thermal Conductivity Values
Hi all – I’m intrigued by Armacell’s insulating foam material made from recycled PET bottles. However, I don’t understand their units for thermal conductivity, or how to convert them to R-values. I’d appreciate your help.
They give their units as W/(m•K). An example value is 0.034 for their least dense version. I thought the metric R-value unit was (K•m²)/W, and I don’t understand their unit.
They also give an alternate unit of BTU.in/FT².hr.°F.
I don’t know what that is, or what some of those periods are for. I thought R-value in American units was °F•ft²•h/BTU.
How can I convert these units into R-values?
Thanks for your help.
p.s. Here’s a screenshot of their spec sheet with these units: https://imgur.com/gallery/BFHazcC
And here’s their product website: https://local.armacell.com/en/armaform-pet-foam-cores/download/products/
JD Composites built a fascinating house in Nova Scotia out of SIPs made from Armacell’s PET foam.
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