The left is a standard wall, 3/4" siding, 1/2" sheathing, batt insulation and 1/2" sheetrock, if you remove the siding and apply 1-1/4" of hemp-lime to the sheathing, 1/2" furring for condensation then replace the siding you get what's on the right side. Notice how much heat has penetrated the standard wall and how little by adding the hemp-lime, this can be blown on like concrete or hand applied. The temperature reads 4.1C for the standard wall and 1.2C for the wall with the upgrade after 400-minutes, a 70% reduction.

That's a fairly radical improvement in thermal resistance, the hemp adds insulation to the lime mortar and by having the furring strips the conduction from the siding is greatly reduced. This will matter where it's windy and cold. I've done a lot of combinations now and this seems to add the most for the least, the hemp-lime fungus resistant, allows moisture to move and is basically fireproof. Insulation board can be used instead of the hemp-lime.

 

These are only conduction so not a full analysis but reveal much, this free software is basic, yet you can modify properties and all, the desktop download gives better results and the pages have a choice of practical setups to download and use that are very practical: 

http://energy.concord.org/energy2d/thermal-bridge.html

Property values I used, not confident on all these yet, most from engineeringtoolbox.com:

pine    glass wool
0.13    0.025
480    1030
25      0.025

insul-board  hemp-lime
0.048           0.06
1450            1600
35                275

gypsum    plaster
0.17          0.71
1090         900
2300         23 

Views: 993

Reply to This

Replies to This Discussion

Thanks for the link, this is a great app! We do lime plaster finishes on our historic restorations, so adding hemp is a no-brainer; thanks for the suggestion.

RSS

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Home Energy Magazine posted a blog post

Natural Gas is Becoming Less Attractive

The United States and Canada have been fortunate to have access to natural gas for space heating,…See More
1 hour ago
Jim Gunshinan posted a blog post

A Healthy Home and a Healthy Bottom Line

There has been a lot of interest of late in the weatherization and broader home performance…See More
1 hour ago
Luke Langhals commented on Tom White's video
Thumbnail

Passivhaus Goes Personal

"Great video. This shows that Passive House isn't all about Energy. Selling it to customers…"
1 hour ago
Quinn Korzeniecki added a discussion to the group Building Performance Institute (BPI)
Thumbnail

Home (Performance) for the Holidays: December Newsletter & Stump the Chump!

Give yourself the gift of home performance knowledge this holiday season and check out BPI's…See More
2 hours ago
Barbara Smith's video was featured

Energy Hogs in the Garage

Look around your garage. You probably have appliances, battery chargers, and all sorts of electrical devices that could be adding up to a lot of money and en... From Alliant Energy PowerHouse TV Channel on YouTube.
3 hours ago
Alfie Davis posted a blog post
8 hours ago
Steve Last commented on Tom White's blog post Moving Forward with Home Performance
"Hopefully politicians seeking quick wins for the US economy will see home insulation improvements…"
19 hours ago
Steve Last posted a photo
20 hours ago

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service