For the last couple weeks, Matt and his crew, plus volunteers, have been continuing the second floor Hemcrete installation.
If you’re interested in volunteering for the Nauhaus Prototype Project, please contact Billy.
Click here to view the entire Nauhaus Prototype Construction Chronology.
Current View of Southeast
Current View of Southwest
Hemp Stacked and Waiting
The Trusty Mixer
Adam is the fastest Hemcrete installer in the West!
Support for Upper Forms over CMU Wall
Closeup of Form Attachment
Scaffolding
The forms are built up almost ot the overhangs, and are stuffed by hand.
Completed Window Opening
Thermally broken mounting bracket for roof supports. The pink is foam insulation.
Closeup of Hemcrete in Form
A combination of custom and pre-made forms is used on the 2nd floor.
Love the blog and the information you are providing. I am really interested in using many of your accumulated solutions to a earth friendly home.
Another simple idea I learned from another website, is to bury the air intake for the home and allow the earth to acclimate the air before it enters the home. It will provide warmer air to home in winter and cooler air in the summer. I thought it made so much sense. Cheers, can’t wait for the next post!
Shane,
The feature you mention is usually called an earth tube. We have a modified version on this project. In our application, we are running a loop of pex piping in the ground under the slab. This is connected to a water to air heat exchanger attached to the air intake for the house going to the ERV. This allows us to use the approximately 55degF ground temp to adjust incoming air temp most of the year. In the winter, it’s warming the incoming cold outdoor air and in summer it’s cooling the incoming warmer outdoor air. The advantage for us of this closed loop approach instead of the simpler direct draw through an earthtube is that we don’t have to deal with the possiblity of condensation in the earth tube growing mold and therefore bringing funky air directly into the house.
Hi Clarke,
Would be curious to see how that water to air heat exchanger worked in your ERV system. Do you have any photos of that or sites I could visit to see a system.
Thank you, Adrien
Adrien,
It’s a very simply system. The Pex loop is under the slab. Liquid is pumped through the loop through a heat exchanger in the outside air intake before the ERV. We are installing it for the first time in our Passive House prototype building. Only the loop is in place at this point, so I don’t have any photos for you.
Clarke
It may not be an issue but I would worry about burying an air tube in the ground as during summer months it could condensate 75 degree humid air from outside into a water pool on the surface of the 55 degree earth tube…. a pool that could grow some interesting critters!
I like the mini geothermal loop under the slab~ I am curious to see how it works.
Thanks for promoting green and sustainable building techniques!
-Quint
We definitely agree. That’s why we aren’t using air but liquid in a closed loop to access the ground temperature. Ambient outside air is pulled directly past the heat exchanger coils, heating or cooling the air based on the season. The closed loop is plumbed to the heat exchanger.
Clarke