C. Letellier

I am one of the ones that consider bio char a charged material.   Ladder of material.  Charcoal mostly carbon but with contaminants and small pore size, activated charcoal most contaminants burned out and larger pore size,  Biochar is either charged with nutrients.  Bio means something beyond pores.  We actually need one or two more technical terms to describe it.  Surface area per unit mass as one level?  Added nutrient content per unit mass of carbon(a ratio number maybe?)

As for in situ charging the problem is how long before it makes gain?  If the first year or the first decade it hurts production instead of helping?

For small scale producers I think we are looking at the wrong feedstock.  Instead of wood that must be broken down after conversion what about pre breaking it?  Most farmers are not set up to make or handle larger wood stuff.  What are they set up for?  swathers, balers, bucket loaders  So I would argue the best feed stock is going to be things that we can harvest with that equipment.  nearly every farmer has weedy bales and other stuff that will make small pieces naturally.

The thing to notice is with animals charging actually improves their living conditions, should reduce odors, should help gather ammonia improving fertilizers content.  Guessing the rest will be charged mixing aerobic no turn composting methods with it before application.

Earth berm passive solar with active thermal air add on here.  Solar thermal collector added mid way thru the winter 7 years ago.  I have managed 4 of the last 6 years without heating.(although this last winter shouldn't really count as it was so warm.)  Now most people are going to require more heat.  My criteria has been lighting the heater when I dropped below 50 degrees F.  Had one year in that that I had 2 days below that but was too busy to light the heater.  North central Wyoming at just over 4000 feet in elevation.  Good area for solar so minor advantage there.

thermal collector panel

added interior air circulation

interior circulation added.

The home was built in 1983-1984 and was over insulated for its era.  To meet minimum modern insulation code for this area today, it would need 1 more inch of insulation in the walls and 2 more inches in the ceiling.  Extremely well sealed.  If running the clothes drier something needs to be open or it can back draft either the heater or the water heater.  Full basement and earth berm on 3 sides for the upstairs.  It is less than perfect but given budget constraints and what we knew then I am still incredibly happy with the house as is.

Heating is one really old room propane heater when heated.  The house with 4 people living in it used just over 500 gallons a year.  That ran the heater, clothes drier, water heater, cook stove.  AC wise we never had more than a single 18,000 BTU window air conditioner mounted on the wrong side of the house in the middle of a south facing brown wall.  Worst year in that time it struggled to keep the house comfortable for about 6 weeks.

First off let me say while earth berm or earth sheltered makes some things easier it is not necessary.  A well built modern house can do everything the earth sheltered home can do for the most part.  Tornado and extreme weather event resistance being the exception.  What makes this house work is high thermal mass, well insulated and well sealed and those can be accomplished in almost any home.

Now if I could go back in time and change some things realizing the house was built on a shoestring budget wise.  Listed here are the heating, cooling and fresh air

My #1 answer is that under the build up soil in the middle of the footing under the basement floor there would have been hydronic tubing.   This would have put it roughly 2 feet of earth and concrete over the tubing.  What I am finding now is the set point for the house in winter is basically the basement floor temperature with the systems I have in place now.  If I could start heating under the floor in July or Aug as part of air conditioning the house there should be a 2 to 3 month time delay before it gets to the floor.  The house can use some air conditioning typically into late October.  A 30 watt pump and transfer heat to under the basement from upstairs.  Given our budget even that little one would have been a stretch but if it was in the rest of retrofit is way more doable.

Stretching #1 would be around the basement burying the rest of the dirt side hydronic tubing for cooling primarily but some heating too.  All the dirt was moved anyway so the tubing and some labor would have been the only needed.  The online information suggests that 12,000 BTU's of cooling needs 400 to 600 feet of 3/4" black poly.  Now knowing now I probably need 18,000 BTUs that would have meant worst case was 900 feet of poly.   Now for the sake of argument say the basement hole was 4 feet each direction larger than the basement.  16 x 60 and we only wrapped 3 sides of the basement and lets say we did one half the loop 2 feet out and the other half 4 feet out in each layer.   Simplify and skip curves in the math 64 +18(2) = 100 for the inner half, 68 +20(2) = 108 for the outer half.  Call that 200 ft per layer and 4 layers would have gotten 800 feet cooling there and say another 150 feet under the basement floor.  Start at footing level for coil 1, coil 2 up 2 feet for basement floor level, coil 3 2 more feet up for 2 feet above basement floor level and final 4th coil at 4 feet above basement floor level.  Normal basement that would only leave say 2 feet of cover over the top coil but earth berm there is easily another 6 to 8 feet of cover over it and all that earth was moved anyway for construction so no real added cost that way.  

#2 change: would have been designing the wall for folded path solar thermal air collectors.  Blocking, headers etc.  There again the collector wouldn't have needed to go in to begin with, if the prep work was done originally.

#3 change: buried air inlet tube to moderate incoming air year round.  According to the Ceres greenhouse information 83 feet of 4 inch drain pipe 8 feet down will pull air all winter long and never drop below freezing.  Guessing 2 tubes for enough volume also buried in the berm.  Then if I could run that thru an HRV core heat loss bringing fresh air in would be minimal.  Burying the tube and getting it thru the concrete wall would take some planning.

#4 change here is my write up on the thinking clerestory window design thinking.  Material cost change is small.

#5 change here is my write on roof overhang change?  Most questionable one in the thinking but I believe it would both make the house stronger and increase energy in.  

#6 change.  Do a hydronic ceiling(not floor) in the upstairs.  Summer air conditions,  Winter both heats sometimes and air conditions sometimes.  Carry the heat to the earth based hydronic choosing where the water goes first.   This is without a heat pump but if you found a heat pump needed nearly everything is already there to implement.

Then modern addition would be what if all the windows went to the R20?  R20 windows

combine that with better insulation, better air sealing and most of the heating and cooling needs be covered.  

John C Daley wrote:

If the tank is round the pressure horizontally is being distributed into an arch.  Vertically built correctly the pressure is applied vertically by gravity.  This means the concrete is under compression both directions and thus working with its strength.

T is the tensile force in the tank wall, its in tension, not compression.
This diagram shows how the forces on the tank wall can be shown.

You are assuming the water is denser than the wall material and stuff behind it.  Should be very slightly the opposite.  Water is 62.4 lb/ft^3   the wall material should be in the 64 to 100 range.  If so it should push in harder than it should push out.

suggest you probably don't want to "graze" to hard.  The soil will likely end up compacted bordering on concrete.  If you use the chicken as a mower instead and then water well and do some form of lasagna mulch will likely give you better soil for the next year compared to having the chicken graze
it back to bare dirt.

The comment about meat chickens not being ideal for weed removal I will second.  If you are doing true meat birds it will likely be cornish x birds and they very poor grazers.  And younger multipurpose birds while better are still not as good as adults.

Ben Brownell wrote:I bet there are some crafty 'natural' solutions to sealing earthen wall or cavity to hold water (fairly) long term. How about firing an appropriate clay content wall material in situ? Or coating the surface with a layer of pitch glue, natural latex, or other durable sealant? Or perhaps a compromise like repurposing an above ground pool membrane or similar?

In my case, I'm in an area with some (already well compacted) non-porous subsoil geology, which leads me to think that simply digging in below grade and capping with some barrier to evaporation would work reasonably well.

To the original suggestion, I think well engineered compacted earth with the right kind and proportion of clay could do pretty well as a tank wall - that's essentially what people do to create pond reservoirs. There would be some seepage, and perhaps unwanted biological activity/buildup to manage.

Yes I suspect other possible answers too. Firing clay in situ likely wouldn't work because clay shrinks when fired.  Typically 10% or more.  

But coatings in another thought entirely.  Water glass would close the pores a lot and is food grade.  A number of the natural oils polymerize.  Better answers?

As for pool membranes EDPM pond and pool liners contain an algicide so probably not.  But there is also EDPM rate for incidental food contact.  And I am sure there are others.  Whole point here is to get people thinking.  Also looking for someone who may have tried it and learned lessons to share.

The dream answer is chemically inert, water proof, durable and low cost.  Earthen hole with a concrete liner comes close, if it would work?

As for biology being a problem for drinking water cisterns it would be.  But for aquaponics, or irrigation water tanks probably not.  Gleying is using biology to seal ponds so for a fish tank it might be ideal?  So if we can get close to a seal to begin with would the rest mostly seal of through biologic means?  

Vertesol Eustache wrote:[
The compaction of the earth will still remain, however, it is not a 'pile' and still expands and contracts with changes in moisture content. The failure of your cistern at the joint due to expansion/contraction differential plus shrink/crack of the eath itself, not compaction. A thin plastering over the compacted earth will never hold water for long, you require continuosly reinforced concrete or suitable liner.

Now you are talking about part of what I am trying to figure out.  If the tank is round the pressure horizontally is being distributed into an arch.  Vertically built correctly the pressure is applied vertically by gravity.  This means the concrete is under compression both directions and thus working with its strength.  Keep roots away and it should be tough.  What I started with growing up was just a concrete plaster on dirt and worked well up to the transition to the real concrete.  The ability to add fiber to the cement should make it stronger which they didn't have 60 years.  Trying to figure out if it would be enough? would it work on a larger scale etc?  Is it worth trying?

3 things that likely are objectionable since food safe term present.

1.  For long term forms my mothers recipe included borax.  Don't know if it is food safe or not.  

2.  Have done some paper mache with Tyvek.  Makes a tougher final product.

3.  Other way to toughen was adding a fabric layer.  easiest was an open weave.

Maybe I was as not far off.

homemade


commercial

Nathanael Szobody wrote:That explanation is very helpful.

I would recommend ferrous cement for the projects you describe. Affordable and sturdy. Totally DIY.

Agreed.  Personally instead of steel looking at doing it with basalt mesh and fiber.  The mesh won't be immediately self supporting and will need to be tied to a support frame for first coat.  But from there should be good.  Big thing is it can't rust and spall which with water projects and thin concrete is a real risk.

/basalt mesh

John C Daley wrote:I have to admit I cannot work out what you are saying!
Do you have a poorly made water cistern in the ground?

I grew up around cisterns.  So I have about 35 years using them.  We had the one small one describe first.  Then we moved to our biggest cistern ever.  It was something like 20,000 gallons.  Octagon  16 feet deep with roughly 6 foot flats making the sides.  Next move we built a concrete block cistern that everything went wrong with.  Lots of lessons in what NOT to do.  We had a neighbor with a cistern that I spent a bunch of time repairing and we installed 2 smaller commercial concrete cistern on the hired help houses. And a friend up country a big for another.  Right now while the crappy dying cistern still exists we put city water in instead of building a new one.

So I am actually thinking cistern multiple directions.  Would still like to have the back up cistern here at the house.   Would love to match our big one is size but even a few thousand gallons would be better than nothing

Then dreaming would like rain catchment.(dry area so smaller)  

Dreaming on a big aquaponics based greenhouse and I would want 3 tanks for this.  2 fish and one hot water storage set in an earth berm as the back wall.  Probably 1 to 2 thousand gallons each.  2 are cone bottom tanks.

Then if the solar planning doesn't do enough want another one for a hot water at both the house and the shop.

Big thing is that if it any of this is going to happen would need to keep the cost to a minimum.  Still trying to find an answer that I think might succeed.  Now the ones doing hot water storage the plastic tanks would not be as valid for.  Ideally want to eliminate plastic too.

recognizing I would need fiber etc with these.  Even wondering if maybe doing it in reverse order needed.  Looking at the cheap version of the underground dome homes Tyvec form, spray concrete with fiber, tight wrap of basalt roving, more concrete, more roving more concrete.  Ends up with rough 1 1/2 inches of concrete.  For the dome homes they then spray it with closed cell foam as the final layer.     What if it was then packed in rammed earth/cob with fiber? either with or without the spray foam?

Or maybe simply rammed earth with or without a concrete plaster with an EDPM or other liner inside.  Less ideal because of the added plastic.

I don't have the answers.  Still dreaming and looking.  But the information suggesting rammed doesn't come uncompacted with water was simply suggesting another possible path for the thinking.  Had never seen anything on this.  So I was posting the question here.

Anne Miller wrote:Musing about cisterns ....

It has been years since I saw a concrete cistern as most are fiberglass now days.

When was the last time you saw one?

 See them occasionally.  Neighbor has one too small.  fiberglass gets really expensive if you want any size and won't work for the possible hot water tanks.

The dream answer would be a cistern made out of glass.  Chemically safe and inert.  So have even been paying attention to the 3D printing with glass.  Almost certainly not doable but still on the dream thinking lost.