C. Letellier

Should clarify some of the things above.

Passive solar.  The sun directly puts the energy in the area needed.   Ideally the sun shines directly on the mass inside (ideally dark mass) an enclosed space (probably thru a window).  You could label this one direct solar.  Next level down of passive is reflected sunshine on mass.  For example right now in the early morning the sun hits the white ceiling of my passive solar home.  This light is reflected around the room with some hitting the back wall heating mass directly by reflected light and some hitting furniture carpet etc.  Sort of the final level is sun in hits low mass items, they get hot and heat the air, air flows around and heats the mass.  Last is very ineffective as if you want to heat tons of mass with air you need to flow tons of air past the mass.

Passive solar done right keeps the sun and its heat outside when you don't want it with no effort on your part and lets it in during the times when you do want it.  Because of season lag that may mean you are to hot for a month or 6 weeks or even 2 months in the fall and to cold for the same time period in the spring.  For example on the longest day of the year in this house the sun rises north of the house.  It doesn't get around to the south side of the house until about 10:30.  By which time the eves are shading the top 6 to 8 feet of the wall.  This mean the sunlight doesn't even come close to the clerestory windows up high in the wall.  On the shortest day of the year the sun comes over the mountain shining on the south wall thru the clerestory windows.  As it rise in a flat arc the sun moves across the ceiling while slowly descending on the back wall.  At noon the full power of the sun is shining directly right at the top of the back wall directly heating that concrete.  Then it moves back up the wall and onto the ceiling toward early evening.  From sun up to sun down the light was coming in the clerestory windows.

Now this is a good place to mention other forms of time delay.  You have season delay and annualized.  For example in annualized geothermal I might be storing heat in the middle of summer for use in the middle of winter.  The earth does this naturally about 8 feet down which is why it is supposed to nearly constant at that depth in most places.

Discussion should include solar thermal air based collectors too.  Reason is they are easier to retrofit in many cases.  Simplest form is a wood box  with a glass cover with an absorber in that takes in cold air and puts out warm/hot air.

Solar collectors over heating is only a problem with badly designed systems mostly.  A good system self limits and simply shuts down so the heat stays outside instead of hurting anything.

An advantage of good active thermal collectors is if they are well designed you can simple choose to not bring the heat in.  Leave it where it is or vent it outside for example.

Should also mention PVT systems.  PV is photalvoltaic and the T is thermal so they do both.  The PV part gathers roughly 20% of the energy as electricity.  The T part gathers another 60+% as heat.  At the same time the PV part is kept cooler making it more efficient and also extending its life expectancy.

Then another chart of home energy usage.  Notice this one shows way higher heating percentages.  But government data so guessing it is likely closer to accurate in this case.  This web page has a number of other useful tool for geography etc.

home energy usage US  

Calling this good for now but will try and get back to add more.

Creighton Samuels wrote:


Legionella was unheard of in the United States until PVC piping became the dominant material for plumbing use.  The reason for this is that Legionella defends itself from the heat by forming a "mother" on the inside of a pipe, but copper is a toxic surface to almost every form of single celled life.  I'm pretty sure that just about every tank heater sold in the United States today has a copper lined tank, for this exact reason; so the threat of getting Legionella spores in your lungs from a tank heater is probably an over-blown concern today, no matter what the thermostat is set to.  That said, they are designed to heat to 135 F, in order to be able to provide at least 110 for an extended period of demand; and that is hot enough to slow cook to destruction just about any form of human pathogen known.

Most water heater tanks are actually lined with glass and NOT copper.

you are aware you can stick weld with 2 or 3 12 volt car batteries in series?  24 volts and 1/8" rod is minorly too cold.  You have to stretch the arc length right to breaking point to get a penetrating weld and because of the low voltage it is very easy to break the arc.  Your rod control needs to be nearly perfect.  Add another battery for 36 volts and move up to 5/32 rod and now you are a bit too hot.  You can practically try and bury the arc.  Push hard enough you feel the flux breaking against the steel to keep the arc as short as possible.  3/16 rod is about right for 36 V.  Basically you have an unlimited current source.  Keep the arc short and you have about 3X to 4x of the cold cranking time of the battery before you need to put a charger on your weakest battery running 5/32 and 36 volts.  So if it will crank for 15 minutes say then you probably have about 45 minutes to an hour of welding before needing to recharge the batteries.  It is really interesting to weld with because one of a welder's instinctive means of tracking how he is doing is listening to the welder hum or load up.  This is dead quiet other than crackle of the arc itself.  Are these great welds?  Most definitely NO.  But in many cases they can be adequate welds.  Have always wanted to build a chopper circuit to pull the 3 batteries voltage down to welding good with 1/8" rod.  

Quick PS #1  24V is really hard to strike the arc with.  I normally bounce strike but usually end up drag striking to get this to start
           PS #2  On nice thing about welding off batteries is how totally stable the current is.  No hesitation, great stability.  Noticably better than most welders I typically use.

This is combing thinking from 3 sources.  1.  Self stopping folded path solar collector design.  2.  Discussions of cold plug on mass heater start up.  3. And the video including the discussion of the RMH with too much draw.  Don't know if this will work or not?

Can we make a chimney that does cold plug to shut itself off without draining heat from the mass?   The folded path solar collectors take advantage of having the inlet and outlet at the same height and insulation in the right places to do what amounts to a cold plug stood vertically.  The you(won't let me use character) facing down fills with cold air as the burn comes to an end while the you(same problem) facing up stays filled with warm air/smoke from the shut down to start with and then maintains the warm side of the plug from heat conducted by the uninsulated first riser pipe.  The insulation around the downward one keeps it from conducting cold into the room.  Would stacking a cold plug and a warm plug stop flow in the pipe?  Probably ideally this would have wall jack outlet slightly lower than the top of the upward aimed you(letter) so you could have both plugs fully active.  Picture is the pipes laid out flat but probably you would want them in a triangle with just enough room for the by pass door/damper.  On start up you would open the door so the smoke bypassed both plug locations.  Once it was hot it close the door.  This would add a bit of drag to the system  going around 2 complete reversals of direction plus 2 extra straight runs which is why added draw would be wanted.  To automate this what if a bi-metal spring latch was added to the uninsulated riser pipe.  When that pipe gets hot enough for the latch to trip, the damper is weighted to close.  That would give a time delay while things got started and add the flow restriction only after things get rolling good.  If mounted close to the barrel the uninsulated pipe would be heated by the barrel to aid in start up and towards the end just a bit to help keep it flowing.  Ideally the door/damper should seal well and be somewhat insulated.  The stacked plugs combined with inlet and outlet heights the same in the top of the wall greatly reduces back siphon.

A bit of health and limited finances.   Second limit is I am concentrating on solar first.  Beyond that I would actually like to do rockets in 4 buildings potentially.

1.  My house.  Passive solar mostly with some active active.  Since I started adding active solar, 3 of the last 5 years in northern WY at a bit over 4000 ft elevation I have run without heating the house at all.  But not at a temperature most people would consider acceptable.  Coldest ever the upstairs got down to 42 degrees for one day.(I was gone several days and didn't have time to light heater and it was 36 below out that day and really gray)  Mostly running just over 50 degrees.  And lighting the propane heater when it reaches 50.  My single biggest problem is how tight this house is.  To run the clothes drier something must be opened or it backdrafts either the heater or the water heater.  The house is extremely high mass so changing its temperature is a major undertaking.  Concern over air leaking in when heater off is another part.  Would need major dampers.  Guessing ideal would be J tube here.  Best would be done in the basement and bring the chimney up thru the floor where the current propane heater is located.  Exit would be thru a existing roof jack where the propane goes out now.  When the house was built planning for a wood stove as an option means all the piping going thru the roof is 10" properly UL listed stuff.  Just inside it necks down to 4" for the propane heater currently.  Other big problem is the destruction of storage space along that basement wall.  20 feet of super usable storage would have to be eliminated.  For the house have active solar with 33" x 154" worth of double pane glass.  Have 44" x 152" of double pane glass salvaged this last summer to add to that collector so I can more than double it.  Then on another part of the front wall I have 160"x 48" worth of glass for another collector for solar thermal air.  Also have 53"x58" double pane for a solar thermal hot water box on the goals too.  Till I get that much in and see where I am, I will continue to study rocket here with no action.  Hope is I can get the house so it gets to warm on sunny days in the winter.  Then use geothermal water with no heat pump to air condition the house and act as battery for any long runs of cold gray days.  But would still like the backup of a RMH.  Part of the future solar goals may help with ventilation though because I need a HRV system when on pure solar.  Propane stove dries the house out and never a problem but sealed tighted on pure solar have some moisture problems to solve.  Working on building an HRV core and that would probably solve air in for heater too.


2.  My shop.  Current heat is mostly solar with some coal stoker/wood.  Want to add a geothermal battery out the west wall and down the hill to hold the shop above freezing on it so the solar is starting from a warmer bottom base temperature.  Dream system would be all on solar beyond that.  Still thinking some heat would be need in quick bursts for a day or 2 at a time will be needed so more backup plan here.  Biggest hold up here is effort to clear the space.  Big pieces of steel etc in the way.  Rough guess about 6 ton of stuff to move off that wall and get stored elsewhere.  Probably 3 to 6 days effort just to make the hole in current storage space. Concrete floor and concrete block  wall to 8 foot high.  So stove itself would be simple.  Earth berm outside so getting to the back wall to go out through the 2x6 framed wall just about concrete height would be easy.  Best guess would be want a bigger batch box here with the pipe folded back on itself vertically up the wall.  While I have 40 feet of back wall even clearing 20 feet of it is work.  Other goal here possible would be a used oil burner stove.  From recent glass salvage got (6)  44" square double panes to add to solar thermal air on one end of the building and on the other corner of the building is a 51" wide area beside big doors and I got way more than I need of single pane windows in wood frames that just happen to be 51" so more solar there.

Have roughly 50 feet of 8" brand new stove pipe gathered.  4 barrels gathered.  Have great clay for dirt but would have to haul in sand for cobb.  So I am nibbling towards potential goals.

3.  Is the neighbors shop tool room.  Interior block wall with concrete floor and roof jack accessible at one end.  Still think RMH would be ideal for this location and I am still trying to talk him into it.  He belongs to the build a big fire and choke it to death thinking and convincing him that creosote is not a problem is so far a losing battle.  Likely to win this battle have to get one running to demonstrate.

4.  Want to gather enough material to do both a RMH and solar thermal air on one of the fair grounds buildings for Demo purposes.  The one building would be easy to implement both in.  And done properly wouldn't hardly affect any of that buildings uses.   Would be a matter of gathering enough materials, finding volunteers and talking the fair board into allowing it to happen.  Concrete block wall and floor with windows air paths in and out  and stove jacks could go thru.

I can't tell you much about using it but I can tell you one way of how NOT to use it.  Back in 1984 when my parents built this house they built the cistern with a dry stack concrete block.   It was held together with a yellowish trowel on material on both sides called Q Bond. (we did pour some of the cores in the block full for added strength but not all).  Cistern leak like a sieve.  Turns out Q bond isn't even slightly water proof.  Had to live with the fact for the first winter because we couldn't fix it in cold weather since we filled the cistern and started using it in Nov.  Next summer lined the inside with a trowel on stuff that looked like concrete called thoroseal.  Every few years when we cleaned the cistern did minor repairs.  By about year 20 the whole walls were buckling in.  Added a cross walled of poured concrete in to help and resealed everything.  Lasted about another 5 years and it is falling in again.  The concrete block had somehow rotted away, was literally crumbling such that you could break pieces with bare hands and the soil around the cistern is soaked creating a lot of in pressure.  Best guess is a combination of leakage, constantly varying water levels and efflorescence steadily destroyed the block and the changing stress from water in the soil did the rest.  I would NEVER use it to build a cistern and if I was using it for underground walls I would work on getting multiple layers of waterproofing between it and the dirt.  Plus I would pour all the cores full with rebar in each.

M Ljin wrote:I don’t think it is possible to tell. A thread is a chronological list of posts. Do you mean whether you responded to a thread?

You might be able to engine-search something like “(thread name) AND (your name) site:permies.com”

Or ctrl+F or whatever you use—on the thread, or on your own post list.

The whether I responded on a particular thread.

It might take a bit of extra coding.  When a post is opened if it took my login info and simply searched the whole post thread for my name and put a check or an asterisk at in the main header to indicate I had posted on that thread and should look closer.  Searching small lists is something the computer does really well and even the big posts like the main hugelkulture thread is still a small list for a computer to search.  Then worst case it would be on me to search stuff.  But it would be nice to know I needed to search.  I probably look at 3 to 10 new threads each time I visit.  Doing a search on everyone would reduce the number I could look at

For example I hit the degrowth post from a year ago, a few days ago.  I was scrolling down to respond when I found my response on the thread.  Interestingly my post from a year ago and what I intended to write would have been nearly identical.  The link to the particular website is in my main computer book marks because I use it a few times a year so pulling it out would have been easy.  Now there were 2 comments would have added.  One was a response to someones question who posted after me and one I didn't bother to find and was a discussion of how and why population growth is happening.(it isn't what most people think)  I may still get the second one posted but I didn't find it in a quick youtube search and I lost its bookmark in a computer crash a year ago.

Having been here for a long time I find that I forget what posts I have responded to.   So at the top of a post can we get a symbol that says the post has been responded to.  Maybe with a number following showing the number of responses if it is greater than 1.  Also if the symbol clicked on takes me to my first response in that post.  Having been here 12+ years it is very easy to forget.

PS you are showing your well in and hot out backwards.  Cold to the bottom and hot out of the top.  Add a stratifier if needed so you don't mix them.

Question.  Do you actually need the tank over the stove barrel?  The bottom can't be insulated so you will have radiative heat out the bottom.  Yes it is into a heat bell so maybe not a risk?  Its size will limit storage capacity.  Guessing you will want more storage.  As you stated it will make getting to the heat riser for maintenance difficult.  Material to build the barrel will be somewhat difficult and expensive if done so it doesn't corrode.  ideally would like a much smaller amount of stainless or other material exposed to the fire.

Alternate answer.  There are various youtube videos showing the water "tank" aka wood box, being made with 2X material, plywood, lined with insulation and then that lined with an EDPM which is rates to 200 degrees max working temperature.  Personally since I am a bit over 4000 feet in elevation the boiling point of water is worst case 203 degrees.  So I couldn't ever get much over the 200.  And if my water tank is big enough even getting it close would give time for the fire to burn out.

So my thinking is to build the barrel instead.  Use say 1 1/4" black schedule 40and wind it into a spiral of barrel diameter or slightly larger.  like a giant spring.  Say 3 or 4 full wraps.  Spiral into that say 1/8 inch flat material run thru a slip roll and weld the 2 together into a solid barrel.  The squish boom discussions sound like that size pipe is big enough to keep it from all flashing to steam at once and into a non pressurized system it should be safe anyway.  Now the question it corrosion protection.  Treat this as sacrificial?  Or can the inside of the pipe be cleaned and electoplated in copper or nickel.  Plating inside a pipe would be difficult but what if a piece of monofiliment was blown thru to pull a centering brush with the power wire.  It would be a slow operation.  One other alternate would be an active corrosion prevention system with a sacrificial anode elsewhere in the tank.  Final option here is maybe glass line the pipe.  Still researching this part so no solid guesses as to desired answer here.  Final high price alternative would be the 30 to 40 feet of stainless pipe.

So lets start at the "tank" and work thru the system.  Inside the tank an insulated snorkel up to say 2/3 of the height of the tank and out thru a bulkhead fitting.  From there into Tee with the main part aimed down and an air break aimed up so the whole tank will NOT drain if a leak happens somewhere other than the tank itself.  Take the line down to the bottom of the spiral.  Question in the thinking here is do I want to do a Tesla valve where it goes into the spiral so there is even less chance of it back feeding?  Head pressure backward vs forwards and cold vs hot water should prevent it but a Tesla valve would give added protection.  

Then on the outlet of the spiral a heat riser pipe going as straight up as possible.  (short runner pipe on an angle allowed if needed)  The outlet should go a couple of inches above the water level for the system.  Now want to drop this out and into what amounts to a giant funnel open to the air but with a steam condenser built into the lid.  Condenser borrow from alcohol distillation tricks.  Small amounts of steam generated should return it back to the water.  Now at the bottom of the vertical pipe want something to direct any bubbles into the middle of the pipe so it works like an air lift pump running on steam/a bit of air when needed.  Most of the time the expansion of the water combined with convection should lift the water above the water line so it is flowing into open air and thus a non pressurized system.  Now some large glass bottles above this water line neck down should provide a reset-able refill for the system with easily visible site glass.

From this insulated funnel into piping looking like an ES(program won't let me do just the character) laid on its side.  It is all inside insulation.  This creates a trap to seal the tank.  Only time the water level gets high for the water to return to the tank.  A air vent on the high of the up curve of the pipe, of the tank will let its volume change up and down while preventing it from siphoning the trap completely empty. (air vent back into the top of the funnel

Now for the solar end my thinking has been looking at drain back systems which means I would need a pump.  But done correctly I can get rid of the complexities of heat exchangers and antifreeze.  And if I can do it with PEX tubing, greatly reduced freeze risk if something fails plus reduced cost.  And low wattage DC magnetic drive pumps are readily available.  No seals to fail on the pump and with some in the 30 watt range not really a big solar panel to drive and only needed when the sun shines anyway.

Third component of the thinking is for summer months to include 2 more pumped loops.  One to ground for final cooling inside going to hydronic ceiling system inside  And one to ceiling hydronic system so the hot air inside the house is doing the preheat on the tank.