steve pailet II

all I can say is keep us up to speed on what you decide

Xisca Nicolas wrote:

steve pailet II wrote:that being the case  get a solar panel and battery.. let it run a small circulating pump

Do you mean it is impossible to heat water and send it hot downward to the tank where I want the heat? And then dispose of the cool water again downward?
I really have cliffs and very vertical lines!

if you think heat runs down hill do this.  boil water  in a pan.. put your hand over the top of it. see if you feel heat.  now put your hand below and off to the side.. you tell me which is hotter  hear rises  this is called convection.  Radiation the heat will go all around.  You are not radiating heat till it gets where you are going.. you have a choice you can pump or you can forget it.   Unless you can figure out how to ignore basic thermodynamics.  I doubt that any human has ever figured out how to do this.

What you are asking cannot be done without a real way to move the water and hence to move the heat.  

A comment about falling water.. that and dumping is the only way to get the water to go downhill.    A note about efficiency.  The hotter you get water and store said water in general because the water with a much higher deltaT   that is the heat in the tank vs the heat in the air trying to cool it down  the more inefficient per same volume of water.    When you have a much larger tank at a lower temperature you are going to have much more efficient storage.  All I know is this is a physical reality.  When there is a lower ratio of temp to temp per volume you are going to have that lower temp water stick around.  Most of us have little use for water at 160 unless you want a nice cup of tea.. But.. at 120 you can put your hand in it and wash that tea cup and heat your home

that being the case  get a solar panel and battery.. let it run a small circulating pump

wish I could but honestly it was from a link and I did not look it up.. I just clicked that link

sounds like you might think about doing a thermo siphon heater, but place the heat tank and place it below the cave   This would be totally without pumps or electricity

Xisca Nicolas  when I was talking about the tank I never said it had to be inside .. pipe in the water and insulate the pipe and pump

Ben I think those waxless rings are some sort of foam I do not know how they do with heat  but am guessing that if one is only using 105-110 degree water should not be a problem with them.

xisca  with a big tank and PANELs that actually put the heat into the tank you can get the tank of to 120 degree easily.. adding radiant panels in your living space should allow you to heat just where you want the heat.  Being in a cave you will need to insulate the back of those radiators  and reflect the heat out where you want it.. remember radiant heats everything not just the air..   the rock is going to absorb the heat

Galan   I have also considered how to store the heat.  Big insulated plywood tank, with a foam cover.  solar panels that are drain back and into a long loop of poly just immersed in the tank. then another 2 loop of poly to supply both heat for the radiant and domestic water.  Thinking my tank needs to be 4 x 4 x8 feet nominal.  Once the tank is heated should not be a need for any external heating.  But I think a small water heater would not be a bad thing to add for the domestic  30 gallons for back up.   I am building passively and insulated so I am fairly sure I wont need to play games with the heating loop

David would be interesting to see flir pictures of the heat in those walls.  The point was heat spread along with insulation on the back side so the heat goes where you want it to.  plaster is fine but I do not know how well it spreads the heat.. Much like people doing straight staple up with no heat spreading plates.  There seems to be a monster difference in how well the heat is pushed out to where one wants it.  When I first started my research it was just staple up and some were doing the heat spreading plates..   Years later seeing the feed back on one vs the other..

One can play games and hope for the best or one can just get it right the first time Actually paying attention to those who are experts.  Personally I prefer an expert over a jack leg even if they are in Europe.  Have fun with whatever you choose..   Personally I only want to do it once and not have to retro to fix what I already knew would not work as well.