Chris McClellan

west being best would an arbor of some sort in that space to the west cool thing down enough more and grow enough tasty stuff to be worth building?

air coming in low on the north would be coolest

Put a whole house fan with an insulated door up in the top of the eave or a solar chimney at the peak of the south end with an insulated door on the bottom end where it comes out in the ceiling. Bring in air low on the north side with insulated screened openings between the studs a few inches above the stem wall. Is the ceiling flat in that building or vaulted? How much insulation is in the ceiling?

Has anyone calculated the potential daily heat gain/loss of the existing building or any of the proposed addition designs? My 9'x24' solarium tends to overheat from April to October even with 75 square feet of open windows and a ground coupled brick floor and a good shade tarp and Ohio's relatively shady climate. Designs that add floor space (especially low mass floor) and overhead glass (especially single pane) will be very challenging to manage temperature swing. Starting with a solar wall outside the existing garage door in the door frame would be an expedient way to start the experiment at the PTC and run it for a year before adding a solarium. Additional experiments could include thermal mass water barrels or a cob trombe wall or a cob rocket mass bench placed in the solar footprint of the glass wall.

The primary design challenges I see are
1. Blocking solar gain when it isn't wanted
2. Capturing the solar gain without overheating the space
3. Retaining the solar gain with appropriate thermal mass and insulation. I don't think the thermal benefit of the ground coupled concrete floor comes close to the thermal loss it incurs. This would be a good thing to know.
4. For comfortable space getting "enough" solar gain is a distant 4th in design challenges compared to these others.

Unless you really need more square footage your building will be a lot easier to build and perform a lot better thermally if the addition consists of adding glazing outside the garage door made from repurposed double pane sliding doors. As many of them as possible should be openable and additional venting provided high on the far side of the building--although venting low on the north side and high on the south side would cool the space better.

Leaving the garage door in place and insulating it as much as possible while still being easy to open would make a huge difference in keeping out the sun in summer and retaining the heat gained in the winter.

Improving the building insulation (and venting) would probably make a bigger difference in comfort in the building than the solarium. The ground coupled thermal mass of the floor is a major heat loss in the winter but helps a lot to cool the place in the summer. The ground coupled concrete floor and 6 ton rocket heater in my converted barn apartment does a great job of air conditioning the space in the summer. In winter it does a great job of heating the place BUT only if it is being continually occupied. If not then it takes a couple days of constant firing to bring the bench up to temp and weeks to get the floor up to comfortable. A cob or recycled brick floor over a layer of dry sand would allow us to capture and retain daily thermal gain with less loss. A CottageRocket or rocket mass pebble bench is excellent for quickly heating occasional use space, but a cob bench works better for ground coupling for long term heat storage and for air conditioning because the heat doesn't tend to work its way down into a pebble mass.

--Mud

paul wheaton wrote:Mike and I are thinking of rebranding the ATC as "Permaculture Technology Jamboree"

Click on the thumbs up for this post if you like this idea.

Too many events starting with a p. Unless it stands for Pie.

I have emailed Paul. to get the sauna done would require doing it at the shop I think (except milling, which I haven't heard if the mill is working) and an instructor focusing on the elements of the sauna.

I am excited by the potential for the ATC to gain critical mass to really work well with a lot going on. I could see doing the skiddable rocket sauna as a track all its own to create a building that could be a rocket sauna or an insulated living/sleeping pod that a future homesteader could build at some convenient time and place (like after work in the winter in a suburban garage) from readily available local materials (both industrial scrap and local) then take to their site and use while they are building their site infrastructure. Unlike a $1000 camper this structure could be comfortable, easy to heat, easily repurposed as a guest space or sauna when the "big house" is done and not waste away as a toxic eyesore. A basic skiddable sauna build would include simple round and milled wood carpentry, straw-clay or other natural insulation, cob, and a cottage sized rocket heater.  If we get a good crew we can add to the skill building by harvesting and milling at least some of our own wood, improvising latches and hooks and other accessories from found materials, building or repairing our own windows etc.. Stretch goals could include adding "life support" systems such as catchwater, outdoor shower, a basic bucket compost toilet, and a basic but expandable solar charging system for lights and phone and battery powered tools. Some of these elements could easily become their own course. The idea here is to gain experience and confidence and perspective in creating a handsome and functional and expedient portable shelter.
--Uncle Mud

I'm so excited to see the experiment under way, and so beautifully detailed. How is the dust? If you are getting dusting I get good results painting cob and wood and limewash with a coat of clear home made milk paint. It just gives a little gloss and kills the dust. I was able to visit a "Soddie" last year which was our Prairie ancestors' version of the Wofati. They used limewash to brighten and seal the interior as well.  Above beds and cooking surfaces they plastered with newspapers or cloth or whatever they could get to keep the dirt from settling on them. A "canopy" bed with insulating curtains was pretty normal before central heating too. https://www.patreon.com/posts/22384870

if you are experiencing any dusting on your beautiful interior lime walls you can seal them with clear or tinted milk paint. fresh lime will dust less than stuff that has been sitting in a bag for a while so just put another layer on when you feel it is fading. I am watching your adventure with great interest.

I suspect it would work well while it is really cold out until the mass started to warm up. I've wanted to try one with a horizontal exhaust at the lowest point and a chimney on an up-down tee on the end to let overly cold gasses just fall out and give a little draw when the gasses get warmer after it has been running a while. I'm not sure the heat riser I built here has enough thrust to push the gasses all the way through without the help of the heated final chimney. Kirk Mobert actually built one one time that ran the chimney down hill to cause thrust by taking all o the heat out of the exhaust. He said it worked great until it heated up.
---Mud