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: 680

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

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

Rick Karg replied to Carly@AirCycler's discussion The (Small) Cost of Ventilation Without Recovery
"As a member of the ASHRAE 62.2 committee (and president of Residential Energy Dynamics, the author…"
Friday
Bradford E. White replied to Elizabeth Guinn's discussion ERV in need of backflow preventer.
"I would use an in-line backdraft damper such as Artis Industries or the ones made by Fantech and…"
Thursday
Kim Tanner posted a video

Wireless Air Leakage Testing

This webinar will discuss the use of WiFi technology to conduct and document blower door and duct leakage tests for compliance with local energy codes. The s...
Thursday
Profile IconPerry Grossman, Daniel Pate and Ottawa Furnace Filters joined Home Energy Pros
Thursday
Kirsten Richnavsky added a discussion to the group Building Performance Institute (BPI)
Thumbnail

Breaking the link between unhealthy homes and unhealthy kids

Listen in on IAQ Radio to a discussion on reducing the household triggers that cause asthmaattacks…See More
Thursday
Kirsten Richnavsky posted a discussion

Breaking the link between unhealthy homes and unhealthy kids

Listen in on IAQ Radio to a discussion on reducing the household triggers that cause asthmaattacks…See More
Thursday
Kim Tanner posted events
Thursday
Ottawa Furnace Filters posted a blog post

Some Useful Information about Furnace Air Filters

There is not much we can do about the air pollution outside of a house in Ottawa, Canada, but we…See More
Thursday

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service